U.S. patent application number 15/573035 was filed with the patent office on 2018-05-03 for charging system and charging method for terminal and power adapter.
The applicant listed for this patent is GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP., LTD.. Invention is credited to Chen TIAN, Jialiang ZHANG.
Application Number | 20180123383 15/573035 |
Document ID | / |
Family ID | 59499282 |
Filed Date | 2018-05-03 |
United States Patent
Application |
20180123383 |
Kind Code |
A1 |
TIAN; Chen ; et al. |
May 3, 2018 |
CHARGING SYSTEM AND CHARGING METHOD FOR TERMINAL AND POWER
ADAPTER
Abstract
A charging system, a charge method, and a power adapter are
provided. The charging system includes a battery, a first
rectifying circuit, a switch circuit, a transformer, a second
rectifying circuit, a sampling circuit, and a control circuit. The
control circuit outputs a control signal to the switch circuit, and
regulates a duty cycle of the control signal according to the
current sampling value so that the voltage with the third pulsating
waveform satisfies a requirement of charging the battery.
Inventors: |
TIAN; Chen; (Dongguan City,
Guangdong, CN) ; ZHANG; Jialiang; (Dongguan City,
Guangdong, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP., LTD. |
Dongguan City, Guangdong |
|
CN |
|
|
Family ID: |
59499282 |
Appl. No.: |
15/573035 |
Filed: |
January 7, 2017 |
PCT Filed: |
January 7, 2017 |
PCT NO: |
PCT/CN2017/070541 |
371 Date: |
November 9, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02M 1/44 20130101; H01M
10/44 20130101; H02M 3/33569 20130101; H02J 7/007188 20200101; H02M
7/04 20130101; H02J 7/045 20130101; H02M 3/33592 20130101; H02J
7/022 20130101; H02J 7/00304 20200101; H02J 7/0049 20200101; H02J
7/00712 20200101; H02J 7/00043 20200101; H02M 3/335 20130101; H02M
3/33576 20130101; H02M 7/06 20130101; H02M 3/33507 20130101; H02J
7/0047 20130101; H02J 7/0042 20130101; H02J 7/04 20130101; H01M
10/0525 20130101; H02J 7/00036 20200101; G01R 31/3842 20190101;
H01M 10/4257 20130101; H02J 7/007 20130101; H02J 2007/10 20130101;
H02J 7/00 20130101; H02J 7/008 20130101; H02M 5/04 20130101; H02M
2001/0009 20130101; H02J 7/00711 20200101; H02J 7/2434 20200101;
Y02E 60/10 20130101; H01M 2010/4271 20130101; H02J 7/0029 20130101;
H02J 7/0031 20130101; H02J 7/0071 20200101; H02M 3/33523 20130101;
H02M 7/217 20130101; H02J 2207/10 20200101; H02J 7/00714 20200101;
H02J 7/02 20130101; H02J 2207/20 20200101; H02J 7/00034 20200101;
H02J 7/007192 20200101; H02M 1/08 20130101; H02J 7/06 20130101;
H01M 10/425 20130101; H02J 7/027 20130101 |
International
Class: |
H02J 7/04 20060101
H02J007/04; H02M 3/335 20060101 H02M003/335; H02M 1/08 20060101
H02M001/08; H02J 7/02 20060101 H02J007/02; H02J 7/06 20060101
H02J007/06 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 5, 2016 |
CN |
PCT/CN2016/073679 |
Jul 26, 2016 |
CN |
201610600612.3 |
Claims
1. A charging system, comprising: a battery; a first rectifying
circuit, configured to rectify an alternating current to voltage
with a first pulsating waveform; a switch circuit, configured to
modulate the voltage with the first pulsating waveform according to
a control signal; a transformer, configured to output voltage with
a second pulsating waveform according to the modulated voltage with
the first pulsating waveform; a second rectifying circuit,
configured to rectify the voltage with the second pulsating
waveform to voltage with a third pulsating waveform; a first
current sampling circuit, configured to sample current outputted by
the second rectifying circuit to obtain a current sampling value,
the first current sampling circuit selectively operable in a first
current sampling mode and a second current sampling mode; a mode
switch circuit, configured to control the first current sampling
circuit to switch between the first current sampling mode and the,
second current sampling mode; and a control circuit, coupled to the
first current sampling circuit, the mode switch circuit, and the
mode switch circuit, the control circuit configured to output the
control signal to the switch circuit, configured to control the
mode switch circuit to control the first current sampling circuit
operating in the first current sampling mode or the second current
sampling mode based on a charging mode, and configured to regulate
a duty cycle of the control signal according to the current
sampling value so that the voltage with the third pulsating
waveform satisfies a requirement of charging the battery. and
2-31. (canceled)
32. An power adapter, comprising: a first rectifying circuit,
configured to rectify an alternating current to voltage with a
first pulsating waveform; a switch circuit, configured to modulate
the voltage with the first pulsating waveform according to a
control signal; a transformer, configured to output voltage with a
second pulsating waveform according to the modulated voltage with
the first pulsating waveform; a second rectifying circuit,
configured to rectify the voltage with the second pulsating
waveform to voltage with a third pulsating waveform; a first
charging interface, coupled to the second rectifying circuit and
configured to apply the voltage with the third pulsating waveform
to a battery of a terminal through a second charging interface of
the terminal when the second charging interface of the terminal
couples to the first charging interface, wherein the battery is
coupled to the second charging interface; a first current sampling
circuit, configured to sample current outputted by the second
rectifying circuit to obtain a current sampling value, the first
current sampling circuit selectively operable in a first current
sampling mode and a second current sampling mode; a mode switch
circuit, configured to control the first current sampling circuit
to switch between the first current sampling mode and the second
current sampling mode; and a control circuit, coupled to the first
current sampling circuit, the mode switch circuit, and the switch
circuit, the control circuit configured to output the control
signal to the switch circuit, configured to control the mode switch
circuit to control the first current sampling circuit operating in
the first current sampling mode or the second current sampling mode
based on a charging mode, and configured to regulate a duty cycle
of the control signal according to the current sampling value so
that the voltage with the third. pulsating waveform satisfies a
requirement of charging.
33. The power adapter as claimed in claim 32, wherein the control
circuit is further configured to regulate a frequency of the
control signal according to the current sampling value.
34. The power adapter as claimed in claim 32, wherein the charging
interface comprises a power line configured to charge the battery
and a data line configured to communicate with the terminal; the
control circuit communicates with the terminal through the first
charging interface to determine the charging mode that comprises a
first charging mode and a second charging mode.
35. The power adapter as claimed in claim 34, wherein the control
circuit is further configured to control the mode switch circuit to
control the first current sampling circuit operable in the first
current sampling mode, when the control circuit performs a
bidirectional communication with the terminal through the data line
of the first charging interface to determine that the terminal is
charged by the first charging mode; and the control circuit is
further configured to control the mode switch circuit to control
the first current sampling circuit operable in the second current
sampling mode, when the control circuit performs a bidirectional
communication with the terminal through the data line of the first
charging interface to determine that the terminal is charged by the
second charging mode.
36. The power adapter as claimed in claim 32, wherein the first
current sampling circuit comprises: a first resistor, a first end
of the first resistor coupled to an output end of the second
rectifying circuit; a second resistor, a first end of the second
resistor coupled to the output end of the second rectifying
circuit, wherein a resistance of the second resistor is greater
than a resistance of the first resistor; a third resistor, coupled
between the first end of the second resistor and the first end of
the first resistor; a fourth resistor, coupled between a second end
of the second resistor and a second end of the first resistor; and
a current sensor, configured to sample the current outputted by the
second rectifying circuit according to voltage across the first
resistor or voltage across the second resistor.
37. The power adapter as claimed in claim 36, wherein the first
current sampling circuit further comprises: a fifth resistor, a
first end of the fifth resistor coupled to the second end of the
second resistor and a second end of the fifth resistor coupled to
the current sensor; a sixth resistor, a first end of the sixth
resistor coupled to the second end of the second resistor, and a
second end of the sixth resistor coupled to the current sensor; a
first filter capacitor, a first end of the first filter capacitor
coupled to the second end of the fifth resistor and the current
sensor and a second end of the first filter capacitor being
grounded; and a second filter capacitor, a first end of the second
filter capacitor coupled to the second end of the sixth resistor
and the current sensor, and a second end of the second filter
capacitor being grounded.
38. The power adapter as claimed in claim 36, wherein the mode
switch circuit comprises: a first switch, a first end of the first
switch coupled to the second end of the first resistor, and a
control end of the first switch coupled to the control circuit; a
second switch, a first end of the second switch coupled to the
second end of the second resistor, a control end of the second
switch coupled to the control circuit, and a second end of the
second switch coupled to a second end of the first switch.
39. The power adapter as claimed in claim 34, wherein when the
control. circuit performs a bidirectional communication with the
terminal through the data lines in the first charging interface to
determine that the terminal is charged by the first charging mode,
the control circuit sends a first instruction to the terminal, the
first instruction is configured to inquire of the terminal whether
to enable the first charging mode or not; the control circuit
receives a reply instruction responsive to the first instruction
from the terminal, the reply instruction responsive to the first
instruction is configured to indicate that the terminal agrees to
enable the first charging mode.
40. The power adapter as claimed in claim 39, wherein before the
control circuit sends the first instruction to the terminal, the
power adapter charges the terminal through the second charging
mode, and the control circuit sends the first instruction to the
terminal after determining that a charging time of the second
charging mode is longer than a predetermined threshold value.
41. The power adapter as claimed in claim 39, wherein the control
circuit is further configured to control the power adapter through
controlling the switch. circuit so as to adjust a charging current
to a charging current corresponding to the first charging mode, and
before the power adapter uses the charging current corresponding to
the first charging mode to charge the terminal, the control circuit
performs the bidirectional communication with the terminal through
the data lines in the first charging interface to determine a
charging voltage corresponding to the first charging mode and
control the power adapter to adjust a charging voltage to the
charging voltage corresponding to the first charging mode.
42. The power adapter as claimed in claim 41, wherein when the
control circuit performs the bidirectional communication with the
terminal through the data lines in the first charging interface to
determine the charging voltage corresponding to the first charging
mode, the control circuit sends a second instruction to the
terminal, the second instruction is configured to inquire whether
or not a current output voltage of the power adapter is suitable as
a charging voltage of the first charging mode; the control circuit
receives a reply instruction responsive to the second instruction
sent by the terminal, the reply instruction responsive to the
second instruction is configured to indicate that the current
output voltage of the power adapter is suitable, excessively high,
or excessively low; the control circuit determines the charging
voltage of the first charging mode based on the reply instruction
responsive to the second instruction.
43. The power adapter as claimed in claim 41, wherein before the
control circuit controls the power adapter to adjust the charging
current to the charging current corresponding to the first charging
mode, the control circuit further performs the bidirectional
communication with the terminal through the data lines in the first
charging interface to determine the charging current corresponding
to the first charging mode.
44. The power adapter as claimed in claim 43, wherein when the
control circuit performs the bidirectional communication with the
terminal through the data lines in the first charging interface to
determine the charging current corresponding to the first charging
mode, the control circuit sends a third instruction to the
terminal, the third instruction is configured to inquire about a
maximum charging current currently supported by the terminal; the
control circuit receives a reply instruction responsive to the
third instruction sent by the terminal, the reply instruction
responsive to the third instruction is configured to indicate the
maximum charging current currently supported by the terminal; the
control circuit determines a charging current of the first charging
mode based on the reply instruction responsive to the third
instruction.
45. The power adapter as claimed in claim 39, wherein during the
process that the power adapter is operable in the first charging
mode to charge the terminal, the control circuit further performs
the bidirectional communication with the terminal through the data
lines in the first charging interface to continuously adjust the
charging current output to the battery from the power adapter
through controlling the switch circuit,
46-50. (canceled)
51. A charging method of charging a terminal, comprising:
rectifying an alternating current to output voltage with a first
pulsating waveform when a first charging interface of a power
adapter couples a second charging interface of the terminal;
modulating, by controlling a mode switch circuit, the voltage with
the first pulsating waveform, and converting, by a transformer, the
modulated voltage with the first pulsating waveform into voltage
with a second pulsating waveform; rectifying the voltage with the
second pulsating waveform to output voltage with a third pulsating
waveform, and applying the voltage with the third pulsating
waveform to a battery of the terminal through the second charging
interface; sampling current corresponding to the voltage with the
third pulsating waveform to obtain a current sampling value,
wherein the first current sampling circuit is selectively operable
in a first current sampling mode and a second current sampling
mode; and controlling the first current sampling circuit to operate
in the first current sampling mode or the second current sampling
mode according to a charging triode, and regulating a duty cycle of
the control signal according to the current sampling value so that
the voltage with the third pulsating waveform satisfies a
requirement of charging.
52. The charging method as claimed in claim 51, further comprising:
regulating a frequency of the control signal according to the
current sampling value.
53. The charging method as claimed in claim 51, further comprising:
determining the charging mode by a communication between the first
charging interface and the terminal, the charging mode comprising a
first charging mode and a second charging mode.
54. The charging method as claimed in claim 53, further comprising:
controlling the first current sampling circuit to operate in the
first current sampling mode, when a bidirectional communication
between the terminal and the power adapter via. the first charging
interface is established to determine that the terminal is charged
by the first charging mode; and controlling the first current
sampling circuit to operate in the second current sampling mode,
when the bidirectional communication between the terminal and the
power adapter via the first charging interface is established to
determine that the terminal is charged by the second charging
mode.
55. The charging method as claimed in claim 53, further comprising:
when the bidirectional communication between the terminal and the
power adapter via the first charging interface is established to
determine that the terminal is charged by the first charging mode,
sending, by the power adapter, a first instruction to the terminal,
the first instruction configured to inquire of the terminal whether
to enable the first charging mode or not; receiving, by the power
adapter, a reply instruction responsive to the first instruction
from the terminal, the reply instruction responsive to the first
instruction configured to indicate that the terminal agrees to
enable the first charging mode.
56. The charging method as claimed in claim 55, wherein before
sending the first instruction to the terminal, the power adapter
charges the terminal through the second charging mode, and the
charging method comprises: sending, by the power adapter, the first
instruction to the terminal if a charging time of the second
charging mode is longer than a predetermined threshold value.
57. The charging method as claimed in claim 55, further comprising:
determining a charging voltage corresponding to the first charging
mode through the bidirectional communication between the terminal
and the power adapter via the first charging interface, and
controlling the power adapter to adjust a charging voltage to the
charging voltage corresponding to the first charging mode; and
adjusting a charging current of the power adapter to a charging
current corresponding to the first charging mode by controlling a
switch circuit, and charging the terminal by the charging current
corresponding to the first charging mode outputted by the power
adapter.
58-60. (canceled)
61. The charging method as claimed in claim 55, wherein during the
process that the power adapter is operable in the first charging
mode to charge the terminal, the charging method further comprises:
continuously adjusting, by controlling the switch circuit, the
charging current output to the battery from the power adapter
through the bidirectional communication between the terminal and
the power adapter via the first charging interface.
62-66. (canceled)
67. The charging method as claimed in claim 53, wherein the
terminal supports the second charging mode and the first charging
mode, and a charging current of the first charging mode is greater
than a charging current of the second charging mode, wherein the
charging method further comprises: determining, by the power
adapter, that the first charging mode is used to charge the
terminal, through the bidirectional communication between the
second charging interface of the terminal and the adapter;
outputting, by the power adapter, the charging current
corresponding to the first charging mode to charge the battery in
the terminal.
68. The charging method as claimed in claim 67, wherein determining
that the first charging mode is used to charge the terminal,
through the bidirectional communication between the second charging
interface of the terminal and the adapter, comprises: receiving, by
the terminal, a first instruction sent from the power adapter, the
first instruction configured to inquire of the terminal whether to
enable the first charging mode or not; sending, by the terminal, a
reply instruction responsive to the first instruction to the power
adapter, the reply instruction responsive to the first instruction
configured to indicate that the terminal agrees to enable the first
charging mode.
69-78. (canceled)
Description
BACKGROUND
1. Field of Disclosure
[0001] The present disclosure relates to a terminal device
technology, more particularly, to a charging system for a terminal,
a charging method for the terminal, and a power adapter.
2. Description of Related Art
[0002] Currently, mobile terminals (such as a smart phone) are
increasingly popular with consumers. However, the mobile terminals
consume a great amount of power so that they need to be charged
frequently.
[0003] The mobile terminals are usually charged through power
adapters. A power adapter generally includes a primary rectifier
circuit, a primary filter circuit, a transformer, a secondary
rectifier circuit, a secondary filter circuit, and a control
circuit, etc. The power adapter converts input 220V alternating
current (AC) power into a stable low-voltage direct current (DC)
power (such as 5V) suitable for the mobile terminal, so as to
provide power to a power management device and a battery of the
mobile terminal, thus charging the mobile terminal .
[0004] However, as the power of the power adapters increases, for
example, when the power is upgraded from 5 W to a higher power,
such as 10 W, 15 W, 25 W etc., more electronic components that can
sustain a higher power and realize a higher control of accuracy are
needed for complementing each other. This causes size of the power
adapters to increase as well as manufacturing difficulty of the
adapters to also increase.
[0005] In general, current flowing through the power adapter of
related art is detected with a current sensing resistor and an
operational amplifier. The sensing current becomes greater as power
of the power adapter becomes greater. Correspondingly, under the
premise that the operational amplifier is not saturated, the
dynamic range of the detective current is more limited. However,
when the mobile terminal is charged with small current outputted by
the power adapter, a wider dynamic range of the operational
amplifier by using a smaller current sensing resistor or selecting
a lower amplification of the operational amplifier) may result in
inaccuracy of detection of the small current because of the
characteristic of the operational amplifier, which further affects
the application of the power adapter.
SUMMARY
[0006] The present application is based on the inventor's knowledge
and research on the following issues.
[0007] With the power of a power adapter becomes higher, the
battery tends to polarize and the resistance tends to become larger
when the power adapter charges the battery of the mobile terminal;
the battery temperature thus rises to reduce the service life of
the battery. As a result, the reliability and safety of the battery
are affected.
[0008] In addition, when an AC power supplies power, most of the
equipment cannot operate by directly using the AC power. The reason
is that an AC power, such as 220V/50 Hz mains, outputs power
intermittently, and in order not to be "intermittent", electrolytic
capacitors need to be used for energy storage. When the power is at
the wave trough, the power supply is maintained stably by
continuously relying on the energy storage of electrolytic
capacitors. Therefore, when a mobile terminal is charged by an AC
power supply through a power adapter, the AC power, such as 220V AC
power, provided by the AC power supply is first converted into a
stable DC power be supplied to the mobile terminal. However, the
power adapter charges the battery of the mobile terminal, thus
indirectly supplying power to the mobile terminal. The continuity
of power supply can be ensured by the battery. As such, the power
adapter does not need to continuously output a stable DC power when
charging the battery.
[0009] Therefore, one objective of the present disclosure is to
provide a charging system for a terminal. With the charging system,
voltage with a pulsating waveform outputted by a power adapter is
directly applied to a battery of the terminal, thereby
miniaturizing the power adapter, lowering the cost of the power
adapter, and increasing the lifetime of the battery. Besides, two
current sampling modes are alternatively switched to sample the
current, which ensures the sensing function with the compatibility
between sensing precision and dynamic range and expands the scope
of the applications.
[0010] Another objective of the present disclosure is to provide a
power adapter. Still another objective of the present disclosure is
to provide a charging method for a terminal.
[0011] In order to achieve at least one of the above objectives,
one aspect of the present disclosure provides a charging system for
a terminal. The charging system for a terminal includes a power
adapter. The power adapter includes a first rectifying circuit
configured to rectify an alternating current to voltage with a
first pulsating waveform, a switch circuit configured to modulate
the voltage with the first pulsating waveform according to a
control signal, a transformer configured to output voltage with a
second pulsating waveform according to the modulated voltage with
the first pulsating waveform, a second rectifying circuit
configured to rectify the voltage with the second pulsating
waveform to voltage in a third pulsating waveform, a first charging
interface coupled to the second rectifying circuit, a first current
sampling circuit configured to sample current outputted by the
second rectifying circuit to obtain a current sampling value, the
first current sampling circuit selectively operable in a first
current sampling mode and a second current sampling mode, a mode
switch circuit configured to control the first current sampling
circuit to switch between the first current sampling mode and the
second current sampling mode, and a control circuit coupled to the
first current sampling circuit, the mode switch circuit, and the
mode switch circuit. The control circuit is configured to output
the control signal to the switch circuit, configured to control the
mode switch circuit to control the first current sampling circuit
operating in the first current sampling mode or the second current
sampling mode based on a charging mode, and configured to regulate
a duty cycle of the control signal according to the current
sampling value so that the voltage with the third pulsating
waveform satisfies a requirement of charging. The terminal includes
a battery and a second charging interface coupled to the battery,
wherein the voltage with the third pulsating waveform is applied to
the battery when the second charging interface couples to the first
charging interface.
[0012] According to the embodiment of the present disclosure, the
charging system for the terminal controls the power adapter to
output the voltage with the third pulsating waveform, and directly
applies the voltage with the third pulsating waveform output from
the power adapter to the battery in the terminal, so that the fast
charging of the battery directly by the output voltage/current that
is pulsating can be achieved. A magnitude of the output
voltage/current that is pulsating changes periodically. As compared
with the disclosures of charging with constant voltage and constant
current in the related art, the lithium precipitation phenomenon of
the lithium battery can be reduced. The service life of the battery
can be improved. In addition, the probability of arcing and the
force of the contact at the charging interface can further be
reduced to improve the life of the charging interface. It is also
advantageous in reducing the polarization effect of the battery,
improving the charging speed, reducing the battery heat so as to
ensure the safety and reliability when the terminal is charged.
Additionally, because the power adapter outputs the voltage with
the pulsating waveform, there is no necessity to dispose
electrolytic capacitors in the power supply adapter. Not only can
the power adapter be simplified and miniaturized, but the cost can
also be greatly reduced. Additionally, two current sampling modes
are alternatively switched to sample the current, which ensures the
sensing function with the compatibility between sensing precision
and dynamic range and expands the scope of the applications.
[0013] In order to achieve at least one of the above objectives,
another aspect of the present disclosure provides a power adapter.
The power adapter includes a first rectifying circuit configured to
rectify an alternating current to voltage with a first pulsating
waveform, a switch circuit configured to modulate the voltage with
the first pulsating waveform according to a control signal, a
transformer configured to output voltage with a second pulsating
waveform according to the modulated voltage with the first
pulsating waveform, a second rectifying circuit configured to
rectify the voltage with the second pulsating waveform to voltage
in a third pulsating waveform, a first charging interface coupled
to the second rectifying circuit, a first current sampling circuit
configured to sample current outputted by the second rectifying
circuit to obtain a current sampling value, the first current
sampling circuit selectively operable in a first current sampling
mode and a second current sampling mode, a mode switch circuit
configured to control the first current sampling circuit to switch
between the first current sampling mode and the second current
sampling mode, and a control circuit coupled to the first current
sampling circuit, the mode switch circuit, and the mode switch
circuit. The control circuit is configured to output the control
signal to the switch circuit, configured to control the mode switch
circuit to control the first current sampling circuit operating in
the first current sampling mode or the second current sampling mode
based on a charging mode, and configured to regulate a duty cycle
of the control signal according to the current sampling value so
that the voltage with the third pulsating waveform satisfies a
requirement of charging. The first charging interface is configured
to apply the voltage with the third pulsating waveform to a battery
of a terminal through a second charging interface of the terminal
when the second charging interface of the terminal couples to the
first charging interface. The battery is coupled to the second
charging interface.
[0014] According to the embodiment of the present disclosure, the
power adapter outputs the voltage with the third pulsating waveform
through the first charging interface, and directly applies the
voltage with the third pulsating waveform output from the power
adapter to the battery through the second charging interface in the
terminal, so that the fast charging of the battery directly by the
output voltage/current that is pulsating can be achieved. A
magnitude of the output voltage/current that is pulsating changes
periodically. As compared with the disclosures of charging with
constant voltage and constant current in the related art, the
lithium precipitation phenomenon of the lithium battery can be
reduced. The service life of the battery can be improved. In
addition, the probability of arcing and the force of the contact at
the charging interface can further be reduced to improve the life
of the charging interface. It is also advantageous in reducing the
polarization effect of the battery, improving the charging speed,
reducing the battery heat so as to ensure the safety and
reliability when the terminal is charged. Additionally, because the
power adapter outputs the voltage with the pulsating waveform,
there is no necessity to dispose electrolytic capacitors in the
power supply adapter. Not only can the power adapter simplified and
miniaturized, but the cost can also be greatly reduced.
Additionally, two current sampling modes are alternatively switched
to sample the current, which ensures the sensing function with the
compatibility between sensing precision and dynamic range and
expands the scope of the applications.
[0015] In order to achieve at least one of the above objectives,
still another aspect of the present disclosure provides a charging
method for a terminal. The charging method for the terminal
includes the following acts. An alternating current is rectified to
output voltage with a first pulsating waveform when a first
charging interface of a power adapter couples a second charging
interface of the terminal. The voltage with the first pulsating
waveform is modulated by controlling a mode switch circuit. The
modulated voltage with the first pulsating waveform is converted
into voltage with a second pulsating waveform by a transformer. The
voltage with the second pulsating waveform is rectified to output
voltage in a third pulsating waveform. The voltage with the third
pulsating waveform is applied to a battery of the terminal through
the second charging interface. Current corresponding to the voltage
with the third pulsating waveform is sampled to obtain a current
sampling value, where the first current sampling circuit is
selectively operable in a first current sampling mode and a second
current sampling mode. The first current sampling circuit is
controlled to operate in the first current sampling mode or the
second current sampling mode according to a charging mode, and
regulating a duty cycle of the control signal according to the
current sampling value so that the voltage with the third pulsating
waveform satisfies a requirement of charging.
[0016] According to the charging method provided in the embodiment
of the present disclosure, the voltage with the third pulsating
waveform is outputted by controlling the power adapter, and the
voltage with the third pulsating waveform output from the power
adapter is directly applied to the battery of the terminal, so that
the fast charging of the battery directly by the output
voltage/current that is pulsating can be achieved. A magnitude of
the output voltage/current that is pulsating changes periodically.
As compared with the disclosures of charging with constant voltage
and constant current in the related art, the lithium precipitation
phenomenon of the lithium battery can be reduced. The service life
of the battery can be improved. In addition, the probability of
arcing and the force of the contact at the charging interface can
further be reduced to improve the life of the charging interface.
It is also advantageous in reducing the polarization effect of the
battery, improving the charging speed, reducing the battery heat so
as to ensure the safety and reliability when the terminal is
charged. Additionally, because the power adapter outputs the
voltage with the pulsating waveform, there is no necessity to
dispose electrolytic capacitors in the power supply adapter. Not
only can the power adapter simplified and miniaturized, but the
cost can also be greatly reduced. Additionally, two current
sampling modes are alternatively switched to sample the current,
which ensures the sensing function with the compatibility between
sensing precision and dynamic range and expands the scope of the
applications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1A illustrates a block schematic diagram of a charging
system for a terminal that adopts a flyback switching power supply
according to one embodiment of the present disclosure.
[0018] FIG. 1B illustrates a block schematic diagram of a charging
system for a terminal that adopts a forward switching power supply
according to one embodiment of the present disclosure.
[0019] FIG. 1C illustrates a block schematic diagram of a charging
system for a terminal that adopts a push pull switching power
supply according to one embodiment of the present disclosure.
[0020] FIG. 1D illustrates a block schematic diagram of a charging
system for a terminal that adopts a half-bridge switching power
supply according to one embodiment of the present disclosure.
[0021] FIG. 1E illustrates a block schematic diagram of a charging
system for a terminal that adopts a full-bridge switching power
supply according to one embodiment of the present disclosure.
[0022] FIG. 2A illustrates a block schematic diagram of a charging
system for a terminal according to one embodiment of the present
disclosure.
[0023] FIG. 2B illustrates a circuit diagram of a first current
sampling circuit according to another embodiment of the present
disclosure.
[0024] FIG. 3 illustrates a waveform of a charging voltage output
to a battery from a power adapter according to one embodiment of
the present disclosure.
[0025] FIG. 4 illustrates a waveform of a charging current output
to a battery from a power adapter according to one embodiment of
the present disclosure.
[0026] FIG. 5 illustrates a waveform of a control signal output to
a switch circuit according to one embodiment of the present
disclosure.
[0027] FIG. 6 illustrates a schematic diagram of a fast charging
process according to one embodiment of the present disclosure.
[0028] FIG. 7A illustrates a block schematic diagram of a charging
system for a terminal according to one embodiment of the present
disclosure.
[0029] FIG. 7B illustrates a block schematic diagram of a power
adapter having an LC filter circuit according to one embodiment of
the present disclosure.
[0030] FIG. 8 illustrates a block schematic diagram of a charging
system for a terminal according to another embodiment of the
present disclosure.
[0031] FIG. 9 illustrates a block schematic diagram of a charging
system for a terminal according to still another embodiment of the
present disclosure.
[0032] FIG. 10 illustrates a block schematic diagram of a charging
system for a terminal according to yet another embodiment of the
present disclosure.
[0033] FIG. 11 illustrates a block schematic diagram of a sampling
circuit according to one embodiment of the present disclosure.
[0034] FIG. 12 illustrates a block schematic diagram of a charging
system for a terminal according to an additional embodiment of the
present disclosure.
[0035] FIG. 13 illustrates a block schematic diagram of a terminal
according to one embodiment of the present disclosure.
[0036] FIG. 14 illustrates a block schematic diagram of a terminal
according to another embodiment of the present disclosure.
[0037] FIG. 15 illustrates a flowchart of a charging method for a
terminal according to one embodiment of the present disclosure.
DESCRIPTION OF THE EMBODIMENTS
[0038] Embodiments of the present application are illustrated in
detail in the accompanying drawings, in which like or similar
reference numerals refer to like or similar elements or elements
having the same or similar functions throughout the specification.
The embodiments described below with reference to the accompanying
drawings are exemplary and are intended to be illustrative of the
present application, and are not to be construed as limiting the
scope of the present application.
[0039] Before a charging system and a charging method for a
terminal and a power adapter according to the embodiments of the
present disclosure are provided, description of a power adapter for
charging a chargeable device (e.g. a terminal), that is, an
"associated adapter" as called in the following, in the relevant
technology is first described.
[0040] The associated adapter constantly maintains an output
voltage when the associated adapter operates in a constant voltage
mode, such as 5V, 9V, 12V, or 20V, etc.
[0041] Voltage output from the associated adapter is not suitable
to be directly applied to two terminals of a battery, rather, the
voltage output from the associated adapter needs to be first
converted through a converter circuit in a chargeable device (such
as a terminal) so as to obtain an expected charging voltage and/or
a charging current by a battery in the chargeable device (such as a
terminal).
[0042] The converter circuit is configured to convert the voltage
output from the associated adapter so as to satisfy the expected
requirement of the charging voltage and/or the charging current by
the battery.
[0043] As an example, the converter circuit may refer to a charging
management module, such as a charging IC in the terminal, which is
configured to manage the charging voltage and/or the charging
circuit of the battery during the charging process of the battery.
The converter circuit has a function of a voltage feedback module
and/or a function of a current feedback module to manage the
charging voltage and/or the charging circuit of the battery.
[0044] For example, the charging process of the battery may include
at least one of a trickle charging stage, a constant current
charging stage, and a constant voltage charging stage. During the
trickle charging stage, the converter circuit can utilize a current
feedback loop so that a current entering into the battery satisfies
a magnitude of the charging current expected by the battery (such
as a first charging current) in the trickle charging stage. During
the constant current charging stage, the converter circuit can
utilize the current feedback loop so that the current entering into
the battery satisfies magnitude of the charging current expected by
the battery (such as a second charging current, the second charging
current may be greater than the first charging current) in the
constant current charging stage. During the constant voltage
charging stage, the converter circuit can utilize a voltage
feedback loop so that voltage applied to the two terminals of the
battery satisfies a magnitude of the charging voltage expected by
the battery in the constant voltage charging stage.
[0045] As an example, when the voltage output from the associated
adapter is greater than the charging voltage expected by the
battery, the converter circuit can be configured to step down the
voltage output from the associated adapter so that the charging
voltage obtained after buck conversion satisfies the charging
voltage expected by the battery. As another example, when the
voltage output from the associated adapter is less than the
charging voltage expected by the battery, the converter circuit can
be configured to boost the voltage output from the associated
adapter so that the charging voltage obtained after the boost
conversion satisfies the charging voltage expected by the
battery.
[0046] In yet another example, a constant 5V voltage output from
the associated adapter is taken as an example. When the battery
includes a single cell (take a lithium battery cell for example, a
charging cut-off voltage of a single cell is 4.2V), the converter
circuit (such as a buck circuit) can step down the voltage output
from the associated adapter so that the charging voltage obtained
after bucking satisfies the charging voltage expected by the
battery.
[0047] In yet another example, the constant voltage of 5V output
from the associated adapter is taken as an example. When the
battery is a battery having two or more than two single cells (take
the lithium battery cell for example, the charging cut-off voltage
of the single cell is 4.2V) connected in series, the converter
circuit (such as a boost circuit) can boost the voltage output from
the associated adapter so that the charging voltage obtained after
boosting satisfies the charging voltage expected by the
battery.
[0048] Because the converter circuit is limited by low conversion
efficiency of the circuit, electrical energy that is not converted,
is dissipated in a form of heat. This heat will accumulate inside
the chargeable device (such as the terminal), where a design space
and a heat dissipation space of the chargeable device (such as the
terminal) are both limited (for example, a physical size of a
mobile terminal used by a user becomes increasingly thin and light,
and a great number of electronic components are closely arranged
inside the mobile terminal to enhance performance of the mobile
terminal). Not only does it create increased difficulty of
designing the converter circuit, but also it is very difficult to
dissipate heat accumulated inside the chargeable device (such as
the terminal) in a timely manner, thus causing the chargeable
device (such as the terminal) to become abnormal.
[0049] For example, heat accumulated by the converter circuit is
likely to cause thermal interference with electronic components
near the converter circuit so that the electronic components work
abnormally; and/or, for example, the heat accumulated on the
converter circuit is likely to shorten service lives of the
converter circuit and the electronic components nearby; and/or, for
example, the heat accumulated on the converter circuit is likely to
cause thermal interference with the battery so that the battery
charges and discharges abnormally; and/or, for example, the heat
accumulated on the converter circuit is likely to raise temperature
of the chargeable device (such as the terminal) so that the user
experience is affected when the user charges; and/or, for example,
the heat accumulated on the converter circuit is likely to cause a
short circuit of the converter circuit itself so that the battery
charges abnormally when the voltage output from the associated
adapter is directly applied to the two terminals of a battery.
Under the circumstances that the battery is over charged for a long
time, the battery can even explode, which in turn causes a certain
security concern.
[0050] A power adapter according to the embodiment of the present
disclosure can acquire battery state information. The battery state
information at least includes a current battery level information
and/or voltage information. The power adapter adjusts an output
voltage of the power adapter itself based on the acquired battery
state information to satisfy a charging voltage and/or a charging
current expected by the battery. Voltage outputted by the power
adapter after adjustment can be directly applied to two terminals
of the battery to charge the battery. In some embodiments, an
output of the power adapter may be voltage with a pulsating
waveform.
[0051] The power adapter has functions of a voltage feedback module
and a current feedback module, to achieve the management of the
charging voltage and/or the charging circuit of the battery.
[0052] The power adapter adjusting the output voltage of the power
adapter itself based on the acquired battery state information may
refer to the power adapter can acquire the battery state
information in a real-time manner and adjust the voltage output
from the power adapter itself based on real-time state information
of the battery acquired every time, to satisfy the charging voltage
and/or the charging current expected by the battery.
[0053] The power adapter adjusting the output voltage of the power
adapter itself based on the battery state information acquired in a
real-time manner may refer to the power adapter can acquire current
state information of the battery at different times during a
charging process as the charging voltage of the battery continues
to rise during the charging process, and adjust the output voltage
of the power adapter itself based on the current state information
of the battery in a real-time manner to satisfy the charging
voltage and/or the charging current expected by the battery. The
voltage output from the power adapter after adjustment can be
directly applied to the two terminals of the battery to charge the
battery.
[0054] For example, the charging process of the battery may include
at least one of a trickle charging stage, a constant current
charging stage, and a constant voltage charging stage. During the
trickle charging stage, the power adapter can output a first
charging current to charge the battery so as to satisfy the
charging current expected by the battery (in some embodiments, the
first charging current may be current with a pulsating waveform).
During the constant current charging stage, the power adapter can
utilize a current feedback loop so that a current output from the
power adapter and enters into the battery satisfies the charging
current expected by the battery (for example, a second charging
current, the second charging current may similarly be a current
with a pulsating waveform, the second charging current may be
greater than the first charging current, a peak value of the
current with the pulsating waveform of the constant current
charging stage may be greater than a peak value of the current with
the pulsating waveform of the trickle charging stage, and a
constant current of the constant current charging stage may refer
to the peak value or an average value of the current with the
pulsating waveform basically remaining unchanged). During the
constant voltage charging stage, the power adapter can utilize a
voltage feedback loop so that voltage (that is, the voltage with
the pulsating waveform) outputted from the power adapter to a piece
of chargeable device (such as a terminal) in the constant voltage
charging stage is maintained constantly.
[0055] For example, the power adapter according to the embodiment
of the present disclosure can be mainly configured to control the
constant current charging stage of the battery in the chargeable
device (such as the terminal). In other embodiments, functions of
controlling the trickle charging stage and the constant voltage
charging stage of the battery in the chargeable device (such as the
terminal) may be cooperatively achieved by the power adapter
according to the embodiment of the present disclosure and an
additional charging chip in the chargeable device (such as the
terminal). When compared with the constant current charging stage,
charging power received by the battery in the trickle charging
stage and the constant voltage charging stage is less, the
efficiency conversion loss and heat accumulation of the charging
chip in the chargeable device (such as the terminal) are thus
acceptable. It is noted that the constant current charging stage or
the constant current stage according to the embodiment of the
present disclosure may refer to the charging mode that controls an
output current of the associated adapter and does not require that
the output current of the power adapter to be maintained completely
unchanged, for example, may refer to that the peak value or the
average value of the current with the pulsating waveform output
from the associated adapter basically remains unchanged or
basically remains unchanged within a period of time. For example,
in practice, the power adapter in the constant current charging
stage usually uses a multi-stage constant current charging method
to charge.
[0056] The multi-stage constant current charging may have N
constant current stages (N is a positive integer not less than 2).
The multi-stage constant current charging uses a predetermined
charging current to start a first charging stage. The N constant
current stages of the multi-stage constant current charging are
sequentially executed from the first stage to the (N-1)th stage.
After a previous constant current stage is changed to a next
constant current stage in the constant current stages, the peak
value or the average value of the current with the pulsating
waveform can become smaller. When a battery voltage reaches a
threshold voltage value for terminating charging, the previous
constant current stage will change to the next constant current
stage in the constant current stages. The current conversion
process between two adjacent constant current stages may be
gradual, or may be a stepped jump.
[0057] In addition, it is noted that the term "terminal" as used in
the embodiments of the present disclosure may include, but is not
limited to, a device configured to be connected via a wired
connection (for example, via a public switched telephone network
(PSTN), a digital subscriber line (DSL), a digital cable, a direct
cable connection, and/or another data connection/network) and/or a
device configured to receive/send a communication signal via a
wireless interface (such as a cellular network, a wireless local
area network (WLAN), a digital television network such as a DVB-H
network, a satellite network, an AM-FM broadcast transmitter,
and/or another communication terminal). A terminal configured to
communicate via a wireless interface may be referred to as a
"wireless communication terminal", a "wireless terminal", and/or a
"mobile terminal". Examples of mobile terminal include, but are not
limited to, a satellite or cell phone; a personal communication
system (PCS) terminal that can combine a cellular radiotelephone,
data processing, facsimile, and data communications capabilities;
may include a radiotelephone, a pager, an Internet/Intranet access,
a Web browser, an electronic organizer, a calendar, and/or a
personal digital assistant (PDA) equipped with a global positioning
System (GPS) receiver; and a common laptop and/or palm type
receiver or some other electronic devices including a
transmitter-receiver radiotelephone.
[0058] In addition, according to the embodiment of the present
disclosure, when the voltage with the pulsating waveform output
from the power adapter is directly applied to the battery of the
terminal so as to charge the battery, the charging current is
characterized by a pulsating wave, such as a clipped sine wave, and
it is understood that the charging current charges the battery in
an intermittent manner. A period of the charging current changes
depending on an input AC power, such as a frequency of an AC grid.
For example, a frequency corresponding to the period of the
charging current is an integer multiple or a reciprocal of the
frequency of the AC grid. Additionally, the charging current
charges the battery in an intermittent manner. A current waveform
corresponding to the charging current may be composed of one pulse
or one group of pulses synchronized with the grid.
[0059] A description of a charging system for a terminal and a
power adapter and a charging method for a terminal according to the
embodiment of the present disclosure is provided as follows with
reference to the figures.
[0060] A description is provided with reference to FIG. 1A to FIG.
14. A charging system for a terminal according to the embodiment of
the present disclosure includes a power adapter 1 and a terminal
2.
[0061] As shown in FIG. 2A and FIG. 2B, the power adapter 1
includes a first rectifying circuit 101, a switch circuit 102, a
transformer 103, a second rectifying circuit 104, a first charging
interface 105, a first current sampling circuit 1061, a mode switch
circuit 115 and a control circuit 107. The first rectifying circuit
101 rectifies an input AC power (mains, such as AC220V) to output
voltage in a first pulsation waveform, such as a voltage in a
clipped pulsating waveform. As shown in FIG. 1A, the first
rectifying circuit 101 may be a full bridge rectifier circuit
constituted by four diodes. The switch circuit 102 is configured to
modulate the voltage with the first pulsating waveform based on a
control signal. The switch circuit 102 may be constituted by a
metal-oxide-semiconductor (MOS) transistor, and perform a peak
clipping modulation to the voltage in the clipped pulsating
waveform through performing a pulse width modulation (PWM) control
to the transistor. The transformer 103 is configured to output
voltage with a second pulsating form based on the voltage with the
first pulsating form thus modulated. The second rectifying circuit
104 is configured to rectify the voltage with the second pulsating
waveform to output voltage in a third pulsating form. The second
rectifying circuit 104 may be constituted by a diode or a MOS
transistor, which can achieve secondary synchronous rectification
so that the third pulsating waveform is synchronized with the
modulated first pulsating waveform. It is noted that the third
pulsating waveform being synchronized with the modulated first
pulsating waveform refers to that a phase of the third pulsating
waveform and a phase of the modulated first pulsating waveform are
consistent, and a change trend of an amplitude of the third
pulsating waveform and a change trend of an amplitude of the
modulated first pulsating waveform are consistent. The first
charging interface 105 and the second rectifying circuit 104 are
connected. The first current sampling circuit 1061 is configured to
sample current outputted by the second rectifying circuit 104 to
obtain a current sampling value. The first current sampling circuit
1061 is selectively operable in a first current sampling mode and a
second current sampling mode. The mode switch circuit 115 is
configured to control the first current sampling circuit 1061 to
switch between the first current sampling mode and the second
current sampling mode. The control circuit 107 is coupled to the
first current sampling circuit 1061, the mode switch circuit 115,
and the switch circuit 102. The control circuit 107 is configured
to output the control signal to the switch circuit 102 to control
the mode switch circuit 115 to control the first current sampling
circuit 1061 operating in the first current sampling mode or the
second current sampling mode based on a charging mode, and
configured to regulate a duty cycle of the control signal according
to the current sampling value so that the voltage with the third
pulsating waveform satisfies a requirement of charging.
[0062] As shown in FIG. 2A, the terminal 2 includes a second
charging interface 201 and a battery 202. The second charging
interface 201 is connected to the battery 202. When the second
charging interface 201 and the first charging interface 105 are
connected, the second charging interface 201 applies the voltage
with the third pulsating waveform to the battery 202 to achieve to
charging of the battery 202.
[0063] In one embodiment of the present disclosure, as shown in
FIG. 1A, the power adapter 1 may adopt a flyback switching power
supply. In greater detail, the transformer 103 includes a primary
winding and a secondary winding. One terminal of the primary
winding is connected to a first output terminal of the first
rectifying circuit 101. A second output terminal of the first
rectifying circuit 101 is grounded. Another terminal of the primary
winding is connected to the switch circuit 102 (for example, the
switch circuit 102 is the MOS transistor, so the another terminal
of the primary winding is connected to a drain of the MOS
transistor). The transformer 103 is configured to output the
voltage with the second pulsating waveform based on the modulated
voltage with the first pulsating waveform.
[0064] The transformer 103 is a high-frequency transformer, which
may have an operating frequency of 50 KHz to 2 MHz. The modulated
voltage with the first pulsating waveform is coupled to a secondary
side by the high-frequency transformer and is output by the
secondary winding. According to the embodiment of the present
disclosure, using the high-frequency transformer can take advantage
of the feature of smaller size of the high-frequency transformer as
compared with a low-frequency transformer (a low-frequency
transformer is also called a power frequency transformer, which is
mainly used for the mains frequency, such as 50 Hz or 60 Hz AC)),
thus achieving the miniaturization of the power adapter 1.
[0065] According to one embodiment of the present disclosure, as
shown in FIG. 1B, the power adapter 1 may adopt a forward switching
power supply. In greater detail, the transformer 103 includes a
first winding, a second winding, and a third winding. A dotted
terminal of the first winding is connected to a second output
terminal of the first rectifying circuit 101 through a backward
diode. A non-dotted terminal of the first winding is first
connected to a dotted terminal of the second winding and then they
are connected to a first output terminal of the first rectifying
circuit 101. A non-dotted terminal of the second winding is
connected to the switch circuit 102. The third winding and the
second rectifying circuit 104 are connected. The backward diode has
the effect of reverse clipping. An induced electromotive force
generated by the first winding can limit an amplitude of a counter
electromotive force through the backward diode, and energy caused
by amplitude limitation is returned to an output of the first
rectifying circuit 101 to charge the output of the first rectifying
circuit 101. In addition, a magnetic field generated by a current
passing the first winding can demagnetize a core of the transformer
so that a magnetic field strength in a transformer core is restored
to an initial state. The transformer 103 is configured to output
the voltage with the second pulsating waveform based on the
modulated voltage with the first pulsating waveform.
[0066] According to one embodiment of the present disclosure, as
shown in FIG. 1C, the power adapter may adopt a push-pull switching
power supply. In greater detail, the transformer 103 includes a
first winding, a second winding, a third winding, and a fourth
winding. A dotted terminal of the first winding is connected to the
switch circuit 102. A non-dotted terminal of the first winding is
first connected to a dotted terminal of the second winding and then
they are connected to a first output terminal of the first
rectifying circuit 101. A non-dotted terminal of the second wining
is connected to the switch circuit 102. A non-dotted terminal of
the third winding is connected to a dotted terminal of the fourth
winding. The transformer 103 is configured to output the voltage
with the second pulsating waveform based on the modulated voltage
with the first pulsating waveform.
[0067] As shown in FIG. 1C, the switch circuit 102 includes a first
MOS transistor Q1 and a second MOS transistor Q2. The transformer
103 includes the first winding, the second winding, the third
winding, and the fourth winding. The dotted terminal of the first
winding is connected to a drain of the first MOS transistor Q1 in
the switch circuit 102. The non-dotted terminal of the first
winding is connected to the dotted terminal of the second winding,
and a node between the non-dotted terminal of the first winding and
the dotted terminal of the second winding is connected to the first
output terminal of the first rectifying circuit 101. The non-dotted
terminal of the second wining is connected to a drain of the second
MOS transistor Q2 in the switch circuit 102. A source of the first
MOS transistor Q1 is first connected to a source of the second MOS
transistor Q2 and then they are connected to a second output
terminal of the first rectifying circuit 101. A dotted terminal of
the third winding is connected to a first input terminal of the
second rectifying circuit 104. The non-dotted terminal of the third
winding is connected to the dotted terminal of the fourth winding,
and a node between the non-dotted terminal of the third winding and
the dotted terminal of the fourth winding is grounded. A non-dotted
terminal of the fourth winding is connected to a second input
terminal of the second rectifying circuit 104.
[0068] As shown in FIG. 1C, the first input terminal of the second
rectifying circuit 104 is connected to the dotted terminal of the
third winding. The second input terminal of the second rectifying
circuit 104 is connected to the non-dotted terminal of the fourth
winding. The second rectifying circuit 104 is configured rectify
the voltage with the second pulsating waveform to output the
voltage with the third pulsating waveform. The second rectifying
circuit 104 may include two diodes. An anode of one diode is
connected to the dotted terminal of the third winding. An anode of
the other diode is connected to the non-dotted terminal of the
fourth winding. Cathodes of the two diodes are connected
together.
[0069] According to one embodiment of the present disclosure, as
shown in FIG. 1D, the power adapter 1 may adopt a half-bridge
switching power supply. In greater detail, the switch circuit 102
includes a first MOS transistor Q1, a second MOS transistor Q2, a
first capacitor C1, and a second capacitor C2. The first capacitor
C1 and the second capacitor C2 are first connected in series and
then they are connected in parallel with output terminals of the
first rectifying circuit 101. The first MOS transistor Q1 and the
second MOS transistor Q2 are first connected in series and then
they are connected in parallel with the output terminals of the
first rectifying circuit 101. The transformer 103 includes a first
winding, a second winding, and a third winding. A dotted terminal
of the first winding is connected to a node between the first
capacitor C1 and the second capacitor C2 connected in series. A
non-dotted terminal of the first winding is connected to a node
between the first MOS transistor Q1 and the second MOS transistor
Q2 connected in series. A dotted end of the second winding is
connected to a first input terminal of the second rectifying
circuit 104. A non-dotted terminal of the second winding is first
connected to a dotted terminal of the third winding and then they
are grounded. A non-dotted terminal of the third winding is
connected to a second input terminal of the second rectifying
circuit 104. The transformer 103 is configured to output the
voltage with the second pulsating waveform based on the modulated
voltage with the first pulsating waveform.
[0070] According to one embodiment of the present disclosure, as
shown in FIG. 1E, the power adapter 1 may adopt a full-bridge
switching power supply. In greater detail, the switch circuit 102
includes a first MOS transistor Q1, a second MOS transistor Q2, a
third MOS transistor Q3, and a fourth MOS transistor Q4. The third
MOS transistor Q3 and the fourth MOS transistor Q4 are first
connected in series and then they are connected in parallel with
output terminals of the first rectifying circuit 101. The first MOS
transistor Q1 and the second MOS transistor Q2 are first connected
in series and then they are connected in parallel with the output
terminals of the first rectifying circuit 101. The transformer 103
includes a first winding, a second winding, and a third winding. A
dotted terminal of the first winding is connected to a node between
third MOS transistor Q3 and the fourth MOS transistor Q4 connected
in series. A non-dotted terminal of the first winding is connected
to a node between first MOS transistor Q1 and the second MOS
transistor Q2 connected in series. A dotted terminal of the second
winding is connected to a first input terminal of the second
rectifying circuit 104. A non-dotted terminal of the second winding
is first connected to a dotted terminal of the third winding and
then they are grounded. A non-dotted terminal of the third winding
is connected to a second input terminal of the second rectifying
circuit 104. The transformer 103 is configured to output the
voltage with the second pulsating waveform based on the modulated
voltage with the first pulsating waveform.
[0071] Therefore, the power adapter 1 can use any of the flyback
switching power supply, the forward switching power supply, the
push pull switching power supply, the half-bridge switching power
supply, and the full-bridge switching power supply to output the
voltage with the pulsating waveform according to embodiments of the
present disclosure.
[0072] In addition to that, as shown in FIG. 1A, the second
rectifying circuit 104 is connected to the secondary winding of the
transformer 103. The second rectifying circuit 104 is configured to
rectify the voltage with the second pulsating waveform to output
the voltage in a third pulsating form. The second rectifying
circuit 104 may be constituted by the diode to achieve secondary
synchronous rectification so that the third pulsating waveform is
synchronized with the modulated first pulsating waveform. It is
noted that the third pulsating waveform being synchronized with the
modulated first pulsating waveform refers to that the phase of the
third pulsating waveform and the phase of the modulated first
pulsating waveform are consistent, and the change trend of the
amplitude of the third pulsating waveform and the change trend of
the amplitude of the modulated first pulsating waveform are
consistent. The first charging interface 105 and the second
rectifying circuit 104 are connected. The sampling circuit 106
includes a first current sampling circuit 1061 and a first voltage
sampling circuit 1062. The sampling circuit 106 is configured to
sample the voltage and/or the current output from the second
rectifying circuit 104 to obtain the voltage sampling value and/or
the current sampling value. The control circuit 107 is connected to
the sampling circuit 106 and the switch circuit 102. The control
circuit 107 outputs the control signal to the switch circuit 102,
and modulates the duty cycle of the control signal based on the
voltage sampling value and/or the current sampling value so that
the voltage with the third pulsating waveform output from the
second rectifying circuit 104 satisfies the charging
requirement.
[0073] As shown in FIG. 1A, the terminal 2 includes the second
charging interface 201 and the battery 202. The second charging
interface 201 is connected to the battery 202. When the second
charging interface 201 and the first charging interface 105 are
connected, the second charging interface 201 applies the voltage
with the third pulsating waveform to the battery 202 to achieve to
charging of the battery 202.
[0074] The voltage with the third pulsating waveform satisfying the
charging requirement refers to that the voltage and a current with
the third pulsating waveform satisfy the charging voltage and the
charging current when the battery is charged. That is, the control
circuit 107 modulates the duty cycle of the control signal, such as
a PWM signal, based on voltage and/or a current output from the
power adapter thus sampled to adjust an output of the second
rectifying circuit 104 in a real-time manner. A closed-loop
regulation control is thus realized so that the voltage in the
third pulsation waveform satisfies the charging requirement of the
terminal 2 to ensure that the battery 202 is safely and reliably
charged. A charging voltage waveform output to the battery 202
being regulated through the duty cycle of the PWM signal is shown
in FIG. 3. A charging current waveform output to the battery 202
being regulated through the duty cycle of the PWM signal is shown
in FIG. 4.
[0075] When modulating the duty cycle of the PWM signal, a
regulating instruction can be generated based on the voltage
sampling value, or the current sampling value, or the voltage
sampling value and the current sampling value.
[0076] Hence, according to the embodiment of the present
disclosure, the voltage in the first pulsation waveform, that is,
the voltage in the clipped pulsating waveform, which is rectified
is directly modulated by performing PWM peak clipping through
controlling the switch circuit 102, and delivered to the
high-frequency transformer to be coupled from the primary side to
the secondary side through the high-frequency transformer, and then
be recovered as the voltage/a current in the clipped pulsating
waveform through synchronous rectification to be directly delivered
to the battery so as to achieve the fast charging of the battery.
An amplitude of the voltage in the clipped pulsating waveform can
be regulated through modulating the duty cycle of the PWM signal.
As a result, the output of the power adapter satisfies the charging
requirement of the battery. It can be seen that the power adapter
according to the embodiment of the present disclosure removes the
electrolytic capacitors on the primary side and the secondary side.
Through using the voltage in the clipped pulsating waveform to
directly charge the battery, the size of the power adapter can be
reduced to miniaturize the power adapter and significantly reduce
the cost.
[0077] In one embodiment of the present disclosure, the control
circuit 107 may be a micro controller unit (MCU). That is, the
control circuit 107 may be a microprocessor integrated with a
switch-driven control function, a synchronous rectification
function, and a voltage and current regulation control
function.
[0078] According to one embodiment of the present disclosure, the
control circuit 107 is further configured to modulate a frequency
of the control signal based on the voltage sampling value and/or
the current sampling value. The PWM signal output to the switch
circuit 102 can thus be controlled to be continuously output for a
period of time and then be stopped. After the output has been
stopped for a predetermined time, the output of the PWM is turned
on again. In this manner, the voltage applied to the battery is
intermittent and the battery is intermittently charged. As a
result, the security worry caused by serious heating when the
battery is continuously charged can be avoided to improve the
reliability and safety of battery charging.
[0079] For a lithium battery, in the low temperature condition, the
polarization tends to be intensified during the charging process
owing the decline of the conductive abilities of the ions and
electrons of the lithium battery itself. The continuous charging
method will make this polarization become even more obvious, and at
the same time increase the possibility of lithium precipitation,
thus affecting the safe performance of the battery. In addition,
the continuous charging will result in continuous accumulation of
heat caused by charging, the interior temperature of the battery
also continuously rises. When the temperature exceeds a certain
limit value, the battery performance will be limited and at the
same time the security worry is increased.
[0080] According to the embodiment of the present disclosure,
through modulating the frequency of the control signal, the power
adapter outputs in an intermittent manner. This situation is
equivalent to that the stationary process of the battery is
introduced during the battery charging process, which can alleviate
the possible lithium precipitation phenomenon caused by
polarization in continuous charging and reduce the effect caused by
continuous accumulation of heat. The temperature is thus decreased
to ensure the reliability and safety of the battery charging.
[0081] The control signal output to the switch circuit 102 may be
shown in FIG. 5. The PWM signal is first continuously output for a
period of time and then is stopped for a period of time, and then
is continuously output for a period of time. As a result, the
control signal output to the switch circuit 102 is intermittent and
the frequency is adjustable.
[0082] As shown in FIG. 1A, the control circuit 107 is connected to
the first charging interface 105. The control circuit 107 is
further configured to communicate with the terminal 2 through the
first charging interface 105 to acquire state information of the
terminal 2. In this manner, the control circuit 107 is further
configured to modulate the duty cycle of the control signal, such
as the PWM signal, based on the state information of the terminal
2, and/or the voltage sampling value and/or the current sampling
value.
[0083] The state information of the terminal 2 may include a
battery level, a battery temperature, the battery voltage,
interface information of the terminal, or path impedance
information of the terminal, etc.
[0084] In greater detail, the first charging interface 105 includes
power lines and data lines. The power lines are configured to
charge the battery. The data lines are configured to communicate
with the terminal 2. When the second charging interface 201 is
connected to the first charging interface 105, the power adapter 1
and the terminal 2 can send a communication inquiry instruction to
each other, and establish a communication connection between the
power adapter 1 and the terminal 2 after receiving a reply
instruction correspondingly. The control circuit 107 can acquire
the state information of the terminal 2 so as to negotiate a
charging mode and the charging parameters (such as the charging
current, the charging voltage) with the terminal 2 and control the
charging process.
[0085] The charging mode supported by the power adapter and/or the
terminal may include a second charging mode and a first charging
mode. A charge rate of the first charging mode is greater than a
charge rate of the second charging mode (for example, a charging
current of the first charging mode is greater than a charging
current of the second charging mode). Generally speaking, the
second charging mode can be understood as the charging mode in
which the rated output voltage is 5V and the rated output current
is less than or equal to 2.5A. In addition, in the second charging
mode, D+ and D- in the data lines in an output port of the power
adapter may be short circuited. However, the first charging mode
according to the embodiment of the present disclosure is different.
In the first charging mode of the embodiment of the present
disclosure, the power adapter can communicate with the terminal by
utilizing D+ and D- in the data lines to achieve data exchange,
that is, the power adapter and the terminal can send a fast
charging instruction to each other. The power adapter sends a fast
charging inquiry instruction to the terminal. The power adapter
acquires the state information of the terminal based on a reply
instruction of the terminal after receiving a fast charging reply
instruction of the terminal to enable the first charging mode. In
the first charging mode, the charging current can be greater than
2.5A, for example, can be up to 4.5A or even greater. However, the
second charging mode according to the embodiment of the present
disclosure is not limited. As long as the power adapter supports
two charging modes, and a charge rate (or current) of one of the
charging modes is greater than a charge rate of the other charging
mode, the charging mode having the slower charge rate can be
understood as the second charging mode. Regarding the charging
power, the charging power corresponding to the first charging mode
can be greater than or equal to 15 W.
[0086] The control circuit 107 communicates with the terminal 2
through the first charging interface 105 to determine the charging
mode. The charging mode includes the first charging mode and the
second charging mode.
[0087] In greater detail, the power adapter and the terminal are
connected through a universal serial bus (USB) interface. The USB
interface may be a normal USB interface, a micro USB interface, or
other type USB interfaces. Data lines in the USB interface are the
data lines in the first charging interface and are configured to
provide a bidirectional communication between the power adapter and
the terminal. The data lines may be a D+ line and/or a D- line in
the USB interface, and the bidirectional communication can refer to
the information exchange between the power adapter and the
terminal.
[0088] The power adapter performs the bidirectional communication
with the terminal through the data lines in the USB interface to
determine that the terminal is charged by the first charging
mode.
[0089] It is noted that during the process that the power adapter
negotiates with the terminal to determine whether or not the
terminal is charged by the first charging mode, the power adapter
may only be connected to the terminal and does not charge the
terminal, or may charge the terminal by the second charging mode,
or may use a small current to charge the terminal. The embodiment
of the present disclosure is not limited in this regard.
[0090] The power adapter adjusts the charging current to a charging
current corresponding to the first charging mode so as to charge
the terminal. After determining to use the first charging mode to
charge the terminal, the power adapter can directly adjust the
charging current to the charging current corresponding to the first
charging mode, or can negotiate with the terminal to determine the
charging current of the first charging mode. For example, the
charging current corresponding to the first charging mode is
determined based on a current power level of the battery in the
terminal.
[0091] According to the embodiment of the present disclosure, the
power adapter does not blindly increase the output current to
perform fast charging. Rather, the power adapter needs to perform
the bidirectional communication with the terminal so as to
negotiate whether the first charging mode can be used or not. As
compared with the prior art, the safety of fast charging process is
increased.
[0092] Optionally, to serve as one embodiment, when the control
circuit performs the bidirectional communication with terminal
through the data lines in the first charging interface to determine
that the terminal is charged by the first charging mode, the
control circuit sends a first instruction to the terminal. The
first instruction is configured to inquire of the terminal whether
to enable the first charging mode or not. The control circuit
receives a reply instruction responsive to the first instruction
from the terminal. The reply instruction responsive to the first
instruction is configured to indicate that the terminal agrees to
enable the first charging mode.
[0093] Optionally, to serve as one embodiment, before the control
circuit sends the first instruction to the terminal, the power
adapter charges the terminal under the second charging mode, and
the control circuit sends the first instruction to the terminal
after determining that a charging time of the second charging mode
is longer than a predetermined threshold value.
[0094] After the power adapter determines that the charging time of
the second charging mode is longer than the predetermined threshold
value, the power adapter can assume that the terminal has
identified itself as a power adapter and can enable a fast charging
inquiry communication.
[0095] Optionally, to serve as one embodiment, after the power
adapter determines to use a charging current greater than or equal
to a predetermined threshold current value to charge for a
predetermined time, the power adapter sends the first instruction
to the terminal.
[0096] Optionally, to serve as one embodiment, the control circuit
is further configured to control the power adapter through
controlling the switch circuit so as to adjust the charging current
to the charging current corresponding to the first charging mode.
In addition, the control circuit performs the bidirectional
communication with the terminal through the data lines in the first
charging interface before the power adapter uses the charging
current corresponding to the first charging mode to charge the
terminal so as to determine a charging voltage corresponding to the
first charging mode and control the power adapter to adjust the
charging voltage to the charging voltage corresponding to the first
charging mode.
[0097] Optionally, to serve as one embodiment, when the control
circuit performs the bidirectional communication with the terminal
through the data lines in the first charging interface to determine
the charging voltage corresponding to the first charging mode, the
control circuit sends a second instruction to the terminal. The
second instruction is configured to inquire whether or not a
current output voltage of the power adapter is suitable as a
charging voltage of the first charging mode. The control circuit
receives a reply instruction responsive to the second instruction
sent by the terminal. The reply instruction responsive to the
second instruction is configured to indicate that the current
output voltage of the power adapter is suitable, excessively high,
or excessively low. The control circuit determines the charging
voltage of the first charging mode based on the reply instruction
responsive to the second instruction.
[0098] Optionally, to serve as one embodiment, before the control
circuit controls the power adapter to adjust the charging current
to the charging current corresponding to the first charging mode,
the control circuit further performs the bidirectional
communication with the terminal through the data lines in the first
charging interface to determine the charging current corresponding
to the first charging mode.
[0099] Optionally, to serve as one embodiment, when the control
circuit performs the bidirectional communication with the terminal
through the data lines in the first charging interface to determine
the charging current corresponding to the first charging mode, the
control circuit sends a third instruction to the terminal. The
third instruction is configured to inquire about a maximum charging
current currently supported by the terminal. The control circuit
receives a reply instruction responsive to the third instruction
sent by the terminal. The reply instruction responsive to the third
instruction is configured to indicate the maximum charging current
currently supported by the terminal. The control circuit determines
a charging current of the first charging mode based on the reply
instruction responsive to the third instruction.
[0100] The power adapter can directly determine the maximum
charging current as the charging current of the fast charge mode,
or set the charging current as a current value that is less than
the maximum charging current.
[0101] Optionally, to serve as one embodiment, during the process
that the power adapter is operable in the first charging mode to
charge the terminal, the control circuit further performs the
bidirectional communication with the terminal through the data
lines in the first charging interface to continuously adjust the
charging current output to the battery from the power adapter
through controlling the switch circuit.
[0102] The power adapter can continuously inquire about current
state information of the terminal, for example, inquire about the
battery voltage, the battery power level, etc., so as to
continuously adjust the charging current output to the battery from
the power adapter.
[0103] Optionally, to serve as one embodiment, when the control
circuit performs the bidirectional communication with the terminal
through the data lines in the first charging interface to
continuously adjust the charging current output to the battery from
the power adapter through controlling the switch circuit, the
control circuit sends a fourth instruction to the terminal. The
fourth instruction is configured to inquire about a current voltage
of the battery in the terminal. The control circuit receives a
reply instruction responsive to the fourth instruction sent by the
terminal. The reply instruction responsive to the fourth
instruction is configured to indicate the current voltage of the
battery in the terminal. The control circuit adjusts the charging
current output to the battery from the power adapter through
controlling the switch circuit based on the current voltage of the
battery.
[0104] Optionally, to serve as one embodiment, the control circuit
adjusts the charging current output to the battery from the power
adapter to a charging current value corresponding to the current
voltage of the battery through controlling the switch circuit based
on the current voltage of the battery and a predetermined
relationship between a battery voltage value and a charging current
value.
[0105] The power adapter can store the relationship between the
battery voltage value and the charging current value in advance.
The power adapter can perform the bidirectional communication with
the terminal through the data lines in the first charging interface
to obtain the relationship between the battery voltage value and
the charging current value stored in the terminal from a terminal
side.
[0106] Optionally, to serve as one embodiment, during the process
that the power adapter is operable in the first charging mode to
charge the terminal, the control circuit further performs the
bidirectional communication with the terminal through the data
lines in the first charging interface to determine whether there is
a bad contact between the first charging interface and the second
charging interface or not. When it is determined that there is a
bad contact between the first charging interface and the second
charging interface, the control circuit controls the power adapter
to exit the quick charging mode.
[0107] Optionally, to serve as one embodiment, before determining
whether there is a bad contact between the first charging interface
and the second charging interface or not, the control circuit is
further configured to receive information for indicating a path
impedance of the terminal from the terminal. The control circuit
sends the fourth instruction to the terminal. The fourth
instruction is configured to inquire about voltage of the battery
in the terminal. The control circuit receives the reply instruction
responsive to the fourth instruction sent by the terminal. The
reply instruction responsive to the fourth instruction is
configured to indicate the voltage of the battery in the terminal.
The control circuit determines a path impedance from the power
adapter to the battery based on the output voltage of the power
adapter and the voltage of the battery. The control circuit
determines whether there is a bad contact between the first
charging interface and the second charging interface or not based
on the path impedance from the power adapter to the battery, the
path impedance of the terminal, and a path impedance of the
charging lines between the power adapter and the terminal.
[0108] The terminal can record the path impedance of the terminal
in advance. For example, since terminals of a same model have a
same structure, path impedances of the terminals are set as a same
value in default setting. Similarly, the power adapter can record
the path impedance of the charging lines in advance. When the power
adapter obtains voltage across two terminals of the battery of the
terminal, a path impedance of an overall path can be determined
based on a voltage drop between the power adapter and the two
terminals of the battery and a path current. Upon on a condition
that the path impedance of the overall path is greater than a sum
of the path impedance of the terminal and the path impedance of the
charging lines, or the path impedance of the overall path minus a
sum of the path impedance of the terminal and the path impedance of
the charging lines is greater than a threshold impedance value, it
is determined that there is a bad contact between the first
charging interface and the second charging interface.
[0109] Optionally, to serve as one embodiment, before the power
adapter exits the quick charging mode, the control circuit further
sends a fifth instruction to the terminal. The fifth instruction is
configured to indicate that there is a bad contact between the
first charging interface and the second charging interface.
[0110] After the power adapter sends the fifth instruction, the
power adapter can exit the first charging mode or reset.
[0111] In the above, the fast charging process according to the
embodiment of the present disclosure is described in detail from
the viewpoint of the power adapter, and the fast charging process
according to the embodiment of the present disclosure is provided
from the viewpoint of the terminal as follows.
[0112] Since the interactions between and relevant characteristics,
functions, etc. of the power adapter and the terminal described
from the terminal side are corresponding to the description from
the power adapter side, a repeated description is not provided
where appropriate to simplify matters.
[0113] According to one embodiment of the present disclosure, as
shown in FIG. 13, the terminal 2 further includes a charging
control switch 203 and a controller 204. The charging control
switch 203, such as a switch circuit constituted by electronic
switch elements, is connected between the second charging interface
201 and the battery 202. The charging control switch 203 is
configured to enable or end a charging process of the battery 202
under a control of the controller 204, so that the charging process
of the battery 202 can be controlled from the terminal side to
ensure the safety and reliability of the charging of the battery
202.
[0114] As shown in FIG. 14, the terminal 2 further includes a
communication circuit 205. The communication circuit 205 is
configured to establish a bidirectional communication between the
controller 204 and the control circuit 107 through the second
charging interface 201 and the first charging interface 105. That
is, the terminal 2 and the power adapter 1 can perform the
bidirectional communication through the data lines in the USB
interface. The terminal 2 supports the second charging mode and the
first charging mode. A charging current of the first charging mode
is greater than a charging current of the second charging mode. The
communication circuit 205 and the control circuit 107 perform a
bidirectional communication to allow the power adapter 1 to
determine using the first charging mode to charge the terminal 2,
so that the control circuit 107 controls the power adapter 1 to
output the charging current corresponding to the first charging
mode to charge the battery 202 in the terminal 2.
[0115] According to the embodiment of the present disclosure, the
power adapter 1 does not blindly increase the output current to
perform fast charging. Rather, the power adapter 1 needs to perform
the bidirectional communication with the terminal 2 so as to
negotiate whether the first charging mode can be used or not. As
compared with the prior art, the safety of fast charging process is
improved.
[0116] Optionally, to serve as one embodiment, the controller
receives a first instruction sent by the control circuit through
the communication circuit. The first instruction is configured to
inquire of the terminal whether to enable the first charging mode
or not. The controller sends a reply instruction responsive to the
first instruction to the control circuit through the communication
circuit. The reply instruction responsive to the first instruction
is configured to indicate that the terminal agrees to enable the
first charging mode.
[0117] Optionally, to serve as one embodiment, before the
controller receives the first instruction sent by the control
circuit through the communication circuit, the power adapter
charges the battery in the terminal through the second charging
mode. After the control circuit determines that a charging time of
the second charging mode is longer than a predetermined threshold
value, the control circuit sends the first instruction to the
communication circuit in the terminal. The controller receives the
first instruction sent by the control circuit through the
communication circuit.
[0118] Optionally, to serve as one embodiment, before the power
adapter outputs the charging current corresponding to the first
charging mode to charge the battery in the terminal, the controller
performs the bidirectional communication with the control circuit
through the communication circuit to allow the power adapter to
determine the charging voltage corresponding to the first charging
mode.
[0119] Optionally, to serve as one embodiment, the controller
receives a second instruction sent by the control circuit. The
second instruction is configured to inquire whether or not a
current output voltage of the power adapter is suitable as the
charging voltage of the first charging mode. The controller sends a
reply instruction responsive to the second instruction to the
control circuit. The reply instruction responsive to the second
instruction is configured to indicate that the current output
voltage of the power adapter is suitable, excessively high, or
excessively low.
[0120] Optionally, to serve as one embodiment, the controller
performs the bidirectional communication with the control circuit
to allow the power adapter to determine the charging current
corresponding to the first charging mode.
[0121] The controller receives a third instruction sent by the
control circuit. The third instruction is configured to inquire
about a maximum charging current currently supported by the
terminal. The controller sends a reply instruction responsive to
the third instruction to the control circuit. The reply instruction
responsive to the third instruction is configured to indicate the
maximum charging current currently supported by the battery in the
terminal to allow the power adapter to determine the charging
current corresponding to the first charging mode based on the
maximum charging current.
[0122] Optionally, to serve as one embodiment, during the process
that the power adapter is operable in the first charging mode to
charge the terminal, the controller performs the bidirectional
communication with the control circuit to allow the power adapter
to continuously adjust the charging current output to the battery
from the power adapter.
[0123] The controller receives a fourth instruction sent by the
control circuit. The fourth instruction is configured to inquire
about a current voltage of the battery in the terminal. The
controller sends a reply instruction responsive to the fourth
instruction to the control circuit. The reply instruction
responsive to the fourth instruction is configured to indicate the
current voltage of the battery in the terminal to allow the power
adapter to continuously adjust the charging current output to the
battery from the power adapter based on the current voltage of the
battery.
[0124] Optionally, to serve as one embodiment, during the process
that the power adapter is operable in the first charging mode to
charge the terminal, the controller performs the bidirectional
communication with the control circuit through the communication
circuit to allow the power adapter to determine whether there is a
bad contact between the first charging interface and the second
charging interface or not.
[0125] The controller receives the fourth instruction sent by the
control circuit. The fourth instruction is configured to inquire
about the current voltage of the battery in the terminal. The
controller sends the reply instruction responsive to the fourth
instruction to the control circuit. The reply instruction
responsive to the fourth instruction is configured to indicate the
current voltage of the battery in the terminal to allow the control
circuit to determine whether there is a bad contact between the
first charging interface and the second charging interface or not
based on the output voltage of the power adapter and the current
voltage of the battery.
[0126] Optionally, to serve as one embodiment, the controller
receives a fifth instruction sent by the control circuit. The fifth
instruction is configured to indicate that there is a bad contact
between the first charging interface and the second charging
interface.
[0127] In order to enable and use the first charging mode, the
power adapter can perform a fast charging communication process
with the terminal. Through one or more handshake negotiations, the
fast charging of the battery is achieved. A detailed description of
the fast charging communication process and various stages of the
fast charging process according to the embodiment of the present
disclosure is provided as follows with reference to FIG. 6. It
should be understood that the communication steps or operations
shown in FIG. 6 are merely examples, and the embodiment of the
present disclosure may further perform other operations or
variations of the various operations in FIG. 6. In addition, the
various stages in FIG. 6 may be performed in an order different
from that presented in FIG. 6, and it may not be necessary to
perform all the operations in FIG. 6. It is noted that the curve in
FIG. 6 is a change trend of a peak value or an average value of a
charging current, rather than an actual charging current curve.
[0128] As shown in FIG. 6, the fast charging process may include
five stages.
[0129] Stage 1:
[0130] After a terminal is connected to a power supply device, the
terminal can detect a type of the power supply device through data
lines D+, D-. When the power supply device is detected as a power
adapter, a current absorbed by the terminal may be greater than a
predetermined threshold current value (for example, may be 1A).
When the power adapter detects that an output current of the power
adapter has been greater than or equal to I2 for a predetermined
time (for example, may be a continuous T1 duration), the power
adapter regards that the terminal has completed the type
identification of the power supply device. The power adapter turns
on a handshake communication between the power adapter and the
terminal. The power adapter sends an instruction 1 (corresponding
to the first instruction as described above) to inquire of the
terminal whether to enable the first charging mode or not (or
called flash charging).
[0131] When the power adapter receives a reply instruction of the
terminal indicating that the terminal does not agree to enable the
first charging mode, the output current of the power adapter is
detected again. When the output current of the power adapter is
still greater than or equal to I2 within a predetermined continuous
time (for example, may be the continuous T1 duration), a request is
sent again to inquire of the terminal whether to enable the first
charging mode or not. The above steps of stage 1 are repeated until
the terminal responds to agree to enable the first charging mode,
or the output current of the power adapter no longer satisfies the
condition of being greater than or equal to I2.
[0132] The fast charging process is turned on after the terminal
agrees to enable the first charging mode. The fast charging
communication process enters a stage 2.
[0133] Stage 2:
[0134] Voltage in a clipped pulsating waveform output from the
power adapter may include plural levels. The power adapter sends an
instruction 2 (corresponding to the second instruction as described
above) to the terminal to inquire of the terminal whether or not an
output voltage of the power adapter matches a current voltage of
the battery (or whether or not suitable, that is, whether or not
suitable as a charging voltage of the first charging mode), that
is, whether or not satisfy the charging requirement.
[0135] The terminal responds that the output voltage of the power
adapter is excessively high or excessively low or matching. If the
power adapter receives a feedback of the terminal that the output
voltage of the power adapter is excessively high or excessively
low, the control circuit adjusts the output voltage of the power
adapter by one level through adjusting a duty cycle of a PWM
signal, and sends the instruction 2 to the terminal again to
re-inquire whether the output voltage of the power adapter matches
or not.
[0136] The above steps of stage 2 are repeated until the terminal
responds to the power adapter that the output voltage of the power
adapter is at a matching level, and the fast charging process
enters a stage 3.
[0137] Stage 3:
[0138] After the power adapter receives the feedback replied by the
terminal that the output voltage of the power adapter is matching,
the power adapter sends an instruction 3 (corresponding to the
third instruction as described above) to the terminal to inquire of
the terminal a maximum charging current currently supported by the
terminal. The terminal responds to the power adapter with the
maximum charging current currently supported by the terminal, and
the fast charging process enters a stage 4.
[0139] Stage 4:
[0140] After the power adapter receives a feedback of the maximum
charging current currently supported replied by the terminal, the
power adapter can dispose an output current reference value of the
power adapter. The control circuit 107 adjusts the duty cycle of
the PWM signal based the output current reference value so that the
output current of the power adapter satisfies the requirement of
the charging current of the terminal, that is, enters the constant
current stage. Here the constant current stage refers to that a
peak value or an average value of the output current of the power
adapter basically remains unchanged (that is, a change amplitude of
the peak value or the average value of the output current is very
small, for example, changes within 5% of the peak value or the
average value of the output current). In other words, a peak value
of a current in a third pulsating waveform remains constant in
every period.
[0141] Stage 5:
[0142] When entering the constant current stage, the power adapter
sends an instruction 4 (corresponding to the fourth instruction as
described above) at every interval of time to inquire of the
terminal a current voltage. The terminal can feed back the current
voltage of the battery of the terminal to the power adapter. The
power adapter can determine whether a USB contact, that is, a
contact between a first charging interface and a second charging
interface is good or not and whether it is necessary to reduce a
current charging current value of the terminal or not based on a
feedback of the current voltage of the battery of the terminal
replied by the terminal. When the power adapter determines that the
USB contact is bad, the power adapter sends an instruction 5
(corresponding to the fifth instruction as described above) and
then resets to enter stage 1.
[0143] Optionally, in some embodiments, when the terminal responds
to the instruction 1 in stage 1, data corresponding to the
instruction 1 can attach data (or information) of a path impedance
of the terminal. Path impedance data of the terminal may be used
for determining whether the USB contact is good or not in stage
5.
[0144] Optionally, in some embodiments, time from where the
terminal agrees to enable the first charging mode to where the
power adapter adjusts the voltage to an appropriate value in stage
2 can be controlled within a certain range. If the time exceeds a
predetermined range, the terminal can determine that a request is
abnormal and resets quickly.
[0145] Optionally, in some embodiments, the terminal can give a
feedback that the output voltage of the power adapter is
suitable/matching to the power adapter when the output voltage of
the power adapter is adjusted to .DELTA.V (.DELTA.V is about 200 to
500 mV) higher than the current voltage of the battery in stage 2.
When the terminal gives a feedback that the output voltage of the
power adapter is not suitable (that is, excessively high or
excessively low) to the power adapter, the control circuit 107
adjusts the duty cycle of the PWM signal based on a voltage
sampling value to adjust the output voltage of the power
adapter.
[0146] Optionally, in some embodiments, a speed of adjusting a
magnitude of the output current of the power adapter can be
controlled within a certain range in stage 4, so as to avoid an
abnormal interruption caused by excessively fast adjustment
speed.
[0147] Optionally, in some embodiments, a change amplitude of the
magnitude of the output current of the power adapter can be
controlled within 5% in stage 5. That is, the constant current
stage is identified.
[0148] Optionally, in some embodiments, the power adapter monitors
a charging circuit impedance in a real-time manner in stage 5. That
is, an overall charging circuit impedance is monitored through
measuring the output voltage of the power adapter and the current
charging current, and reading a battery voltage of the terminal.
When it is detected that the charging circuit impedance is greater
than a path impedance of the terminal plus an impedance of fast
charging data lines, the USB contact is regarded as bad to perform
a fast charging reset.
[0149] Optionally, in some embodiments, after the first charging
mode enables, a communication time interval between the power
adapter and the terminal can be controlled within a certain range
to avoid the fast charging reset.
[0150] Optionally, in some embodiments, a stop of the first
charging mode (or the fast charging process) can be classified into
a recoverable stop and an unrecoverable stop.
[0151] For example, when the terminal detects that the battery is
full or the USB contact is bad, the fast charging is stopped and a
reset is performed to enter stage 1. The terminal does not agree to
enable the first charging mode. The fast charging communication
process does not enter stage 2. At this time, the fast charging
process that has been stopped can be an unrecoverable stop.
[0152] In addition, for example, when there is an abnormal
communication between the terminal and the power adapter, the fast
charging is stopped and the reset is performed to enter stage 1.
After the requirement of stage 1 is met, the terminal agrees to
enable the first charging mode to restore the fast charging
process. At this time, the fast charging process that has been
stopped can be a recoverable stop.
[0153] Additionally, for example, when the terminal detects that
the battery is abnormal, the fast charging is stopped and the reset
is performed to enter stage 1. After entering stage 1, the terminal
does not agree to enable the first charging mode. After the battery
returns to normal and satisfies the requirement of stage 1, the
terminal agrees to enable the first charging mode to restore the
fast charging process. At this time, the fast charging process that
has been stopped can be a recoverable stop.
[0154] The communication steps or operations shown in FIG. 6 are
merely examples. For example, in stage 1, a handshake communication
between the terminal and the power adapter may be initiated by the
terminal after the terminal is connected to the power adapter. That
is, the terminal sends the instruction 1 to inquire of the power
adapter whether to enable the first charging mode (or called flash
charging) or not. When the terminal receives a replay instruction
of the power adapter indicating that the power adapter agrees to
enable the first charging mode, the fast charging process is
enabled.
[0155] The communication steps or operations shown in FIG. 6 are
merely examples. For example, a constant voltage charging stage may
be further included after stage 5. That is, in stage 5, the
terminal can feed back the current voltage of the battery of the
terminal to the power adapter. As voltage of the battery of the
terminal rises continuously, the charging is changed to the
constant voltage charging stage when the current voltage of the
battery of the terminal reaches a threshold constant voltage
charging voltage value. The control circuit 107 adjusts the duty
cycle of the PWM signal based on a voltage reference value (that
is, the threshold constant voltage charging voltage value) so that
the output voltage of the power adapter satisfies the requirement
of the charging voltage of the terminal, that is, the voltage is
basically maintained constantly without change. In the constant
voltage charging stage, the charging current gradually decreases.
When the current drops to a certain threshold value, the charging
is stopped. At this time, the battery is identified as being fully
charged. Here the constant voltage charging refers to that a peak
voltage of the third pulsating waveform is basically maintained
constantly.
[0156] According to the embodiment of the present disclosure,
obtaining the output voltage of the power adapter refers to
obtaining the peak voltage or an average voltage value of the third
pulsating waveform. Obtaining the output current of the power
adapter refers to obtaining a peak current or an average current
value of the third pulsating waveform.
[0157] According to one embodiment of the present disclosure, as
shown in FIG. 7A, the power adapter 1 further includes: a
controllable switch 108 and a filter circuit 109 connected in
series. The serially connected controllable switch 108 and filter
circuit 109 are connected to a first output terminal of the second
rectifying circuit 104. The control circuit 107 is further
configured to control the controllable switch 108 to close when a
charging mode is determined to be the second charging mode, and
control the controllable switch 108 to open when the charging mode
is determined to be a first charging mode. In addition, one or more
small capacitors are further connected in parallel at an output
terminal of the second rectifying circuit 104. Not only can the
noise be reduced, but the occurrence of surge phenomenon is also
reduced. Or, the output terminal of the second rectifying circuit
104 may further be connected to an LC filter circuit or a .pi.
filter circuit to filter the ripple interference. As shown in FIG.
7B, the output terminal of the second rectifying circuit 104 is
connected to the LC filter circuit. It is noted that capacitors in
the LC filter circuit or the .pi. filter circuit are all small
capacitors, which take a very small area.
[0158] The filter circuit 109 includes a filter capacitor. The
filter capacitor can support 5V standard charging, that is,
correspond to the second charging mode. The controllable switch 108
may be constituted by a semiconductor switch device, such as a MOS
transistor. When the power adapter uses the second charging mode
(or called standard charging) to charge the battery in the
terminal, the control circuit 107 controls the controllable switch
108 to close. The filter circuit 109 is connected to the circuit so
that an output of the second rectifying circuit can be filtered. In
this manner, the power adapter can be better compatible with the DC
charging technology. That is, a DC power is applied to the battery
of the terminal to achieve DC charging of the battery. For example,
under normal circumstances, a filter circuit including an
electrolytic capacitor and an ordinary capacitor connected in
parallel would support a small capacitor required by 5V standard
charging (such as a solid state capacitor). Since the electrolytic
capacitor occupies a larger volume, the electrolytic capacitor in
the power adapter can be removed to retain a capacitor having a
smaller capacitance so as to reduce the size of the power adapter.
When the second charging mode is used, a branch where the small
capacitor is located can be controlled to conduct. The current is
thus filtered to achieve a stable low-power output so that the DC
charging of the battery is performed. When the first charging mode
is used, the branch where the small capacitor is located can be
controlled to disconnect. The output of the second rectifying
circuit 104 is not filtered. Voltage/current with a pulsating
waveform is directly output to be applied to the battery, thus
achieving fast charging of the battery.
[0159] With the sampling of an output current of the second
rectifying circuit 104, the first current sampling circuit 1061 can
individually sample two currents flowing through two current
sensing resistors, i.e. a first resistor R1 and a second resistor
R2 as illustrated in FIG. 2B, in another embodiment of the present
disclosure. The mode switch unit 115 is configured to switch the
first current sampling circuit 1061 to operate in a first current
sampling mode or a second current sampling mode.
[0160] The control circuit 107 is configured to control the mode
switch circuit 115 to control the first current sampling circuit
1061 operable in the first current sampling mode, when the control
circuit 107 performs a bidirectional communication with the
terminal through the data line of the first charging interface to
determine that the terminal is charged by the first charging mode.
The control circuit 107 is further configured to control the mode
switch circuit 115 to control the first current sampling circuit
1061 operable in the second current sampling mode, when the control
circuit 107 performs a bidirectional communication with the
terminal through the data line of the first charging interface to
determine that the terminal is charged by the second charging
mode.
[0161] Specifically, as FIG. 2B illustrates, the first current
sampling circuit 1061 includes a first resistor R1, a second
resistor R2, and a current sensor 10611 in another embodiment of
the present disclosure. A first end of the first resistor R1 is
coupled to an output end of the second rectifying circuit 104. A
first end of the second resistor R2 is coupled to the output end of
the second rectifying circuit 104. A third resistor R3 is coupled
between the first end of the second resistor R2 and the first end
of the first resistor R1. A fourth resistor R4 is coupled between a
second end of the second resistor R2 and a second end of the first
resistor R1. A resistance of the second resistor R2 is greater than
a resistance of the first resistor R1, that is the second resistor
R2 is a large resistor while the first resistor R1 is a small
resistor. The current sensor 10611 is configured to sample the
current outputted by the second rectifying circuit 104 according to
voltage across the first resistor R1 or voltage across the second
resistor R2. The current sensor 10611 can include an operational
amplifier.
[0162] As FIG. 2B illustrates, the first current sampling circuit
1061 further includes a fifth resistor R5, a sixth resistor R6, a
first filter capacitor C11, and a second filter capacitor C12.A
first end of the fifth resistor R5 is coupled to the second end of
the second resistor R2, and a second end of the fifth resistor R5
is coupled to the current sensor 10611. A first end of the sixth
resistor R6 is coupled to the second end of the second resistor R2,
and a second end of the sixth resistor R6 is coupled to the current
sensor 10611. A first end of the first filter capacitor C11 is
coupled to the second end of the fifth resistor R5 and the current
sensor 10611. A second end of the first filter capacitor C11 is
grounded. A first end of the second filter capacitor C12 is coupled
to the second end of the sixth resistor R6 and the current sensor
10611, and a second end of the second filter capacitor C12 is
grounded.
[0163] In other words, the first current sampling circuit 1061 can
detect current through the first resistor R1 (a small resistor) and
the second resistor R2 (a large resistor) individually so the first
current sampling circuit 1061 can be selectively operable in two
current sampling modes.
[0164] In another embodiment of the present disclosure, the mode
switch circuit 115 includes a first switch SW1 and a second switch
SW2, as FIG. 2B illustrates. A first end of the first switch SW1 is
coupled to the second end of the first resistor R1, and a control
end of the first switch SW1 is coupled to the control circuit 107.
A first end of the second switch SW2 is coupled to the second end
of the second resistor R2, a control end of the second switch SW2
is coupled to the control circuit 107, and a second end of the
second switch SW2 is coupled to a second end of the first switch
SW1. Both of the first switch SW1 and the second resistor R2 may be
Metal oxide semiconductor (MOS) transistors.
[0165] In this embodiment of the present disclosure, when the
control circuit 107 performs a bidirectional communication with the
terminal through the data line of the first charging interface to
determine that the terminal is charged by the first charging mode,
i.e. a fast charging with high current, the first current sampling
circuit 1061 is operable in the first current sampling mode that
current flowing through the small resistor R1 is sensed, as the
first switch SW1 turns on and the second switch SW2 turns off. When
the control circuit 107 performs a bidirectional communication with
the terminal through the data line of the first charging interface
to determine that the terminal is charged by the second charging
mode, i.e. a standard charging with low current, the first current
sampling circuit 1061 is operable in the second current sampling
mode that current flowing through the large resistor R2 is sensed,
as the first switch SW1 turns off and the second switch SW2 turns
on.
[0166] Accordingly, by using the charging system for the terminal
according to the present disclosure, two current sampling modes are
alternatively switched to sample the current, which ensures the
sensing function with the compatibility between sensing precision
and dynamic range and expands the scope of the applications.
[0167] According to one embodiment of the present disclosure, the
control circuit 107 is further configured to obtain a charging
current and/or a charging voltage corresponding to the first
charging mode based on state information of the terminal when the
charging mode is determined to be the first charging mode, and
modulate a duty cycle of a PWM signal based on the charging current
and/or the charging voltage corresponding to the first charging
mode. That is, when a current charging mode is determined to be the
first charging mode, the control circuit 107 obtains the charging
current and/or the charging voltage corresponding to the first
charging mode based on acquired state information of the terminal,
such as a battery voltage, a battery level, a battery temperature,
operating parameters of the terminal, and power consumption
information of an application running on the terminal, etc., then
modulates the duty cycle of a control signal based on the obtained
charging current and/or charging voltage. As a result, an output of
the power adapter satisfies the charging requirement to achieve the
fast charging of the battery.
[0168] The state information of the terminal includes the battery
temperature. Additionally, when the battery temperature is higher
than a first predetermined threshold temperature or lower than a
second predetermined threshold temperature, the first charging mode
is switched to the second charging mode if the current charging
mode is the first charging mode. The first predetermined threshold
temperature is higher the second predetermined threshold
temperature. In other words, when the battery temperature is
excessively low (for example, the battery temperature lower than
the second predetermined threshold temperature) or excessively high
(for example, the battery temperature higher than the first
predetermined threshold temperature), neither is suitable for fast
charging. Therefore, the first charging mode needs to be switched
to the second charging mode. According to one embodiment of the
present disclosure, the first predetermined threshold temperature
and the second predetermined threshold temperature may be set or
written to a memory of the control circuit (such as an MCU of the
power adapter) depending on practical situations.
[0169] In one embodiment of the present disclosure, the control
circuit 107 is further configured to control the switch circuit 102
to turn off when the battery temperature is higher than a high
temperature protection threshold that is predetermined. That is,
the control circuit 107 needs to adopt a high temperature
protection strategy to control the switch circuit 102 to turn off
when the battery temperature exceeds the high temperature
protection threshold, so that the power adapter stops charging the
battery. The high temperature protection of battery is thus
achieved to improve charging safety. The high temperature
protection threshold may be different from the first predetermined
threshold temperature, or may be the same as the first
predetermined threshold temperature. In at least one embodiment,
the high temperature protection threshold is higher than the first
predetermined threshold temperature.
[0170] In another embodiment of the present disclosure, a
controller is further configured to acquired the battery
temperature, and control a charging control switch to turn off when
the battery temperature is higher than the high temperature
protection threshold that is predetermined. That is, the charging
control switch is turned off through a terminal side to turn off
the charging process of the battery so as to ensure charging
safety.
[0171] In one embodiment of the present disclosure, the control
circuit is further configured to acquire a temperature of the first
charging interface, and control the switch circuit to turn off when
the temperature of the first charging interface is higher than a
predetermined protection temperature. That is, the control circuit
107 also needs to execute the high temperature protection strategy
to control the switch circuit 102 to turn off when the temperature
of the first charging interface exceeds a certain temperature, so
that the power adapter stops charging the battery. The high
temperature protection of charging interface is thus achieved to
improve the charging safety.
[0172] In another embodiment of the present disclosure, the
controller acquires the temperature of the first charging interface
through performing a bidirectional communication with the control
circuit, and controls the charging control switch (see FIG. 13 and
FIG. 14) to turn off when the temperature of the first charging
interface is higher than the predetermined protection temperature.
That is, the charging control switch is turned off through the
terminal side to turn off the charging process of the battery so as
to ensure charging safety.
[0173] In greater detail, in one embodiment of the present
disclosure, the power adapter 1 further includes a drive circuit
110, such as a MOSFET driver, as shown in FIG. 8. The drive circuit
110 is connected between the switch circuit 102 and the control
circuit 107. The drive circuit 110 is configured to drive the
switch circuit 102 to turn on or turn off based on a control
signal. Of course, it is noted that the drive circuit 110 may be
integrated in the control circuit 107 according to other
embodiments of the present disclosure.
[0174] As shown in FIG. 8, the power adapter 1 further includes an
isolation circuit 111. The isolation circuit 111 is connected
between the drive circuit 110 and the control circuit 107 to
achieve signal isolation between a primary side and a secondary
side of the power adapter 1 (or signal isolation between a primary
winding and a secondary winding of the transformer 103). The
isolation circuit 111 may use an optocoupler isolation, or may use
some other isolation. Through disposing the isolation circuit 111,
the control circuit 107 can be disposed on the secondary side of
the power adapter 1 (or a secondary winding side of the transformer
103) to facilitate the control circuit 107 to communicate with the
terminal 2. As a result, the space design of the power adapter 1
becomes simpler and easier.
[0175] In other embodiments of the present disclosure, both the
control circuit 107 and the drive circuit 110 can be disposed on
the primary side. Under the circumstances, the isolation circuit
111 can be disposed between the control circuit 107 and the
sampling circuit 106 to achieve the signal isolation between the
primary side and the secondary side of the power adapter 1.
[0176] In one embodiment of the present disclosure, the isolation
circuit 111 needs to be disposed when the control circuit 107 is
disposed on the secondary side. The isolation circuit 111 may be
integrated in the control circuit 107. In other words, when a
signal is transmitted from the primary side to the secondary side
or from the secondary side to the primary side, the isolation
circuit usually needs to be disposed to perform signal
isolation.
[0177] In one embodiment of the present disclosure, as shown in
FIG. 9, the power adapter 1 further includes an auxiliary winding
and a power supply circuit 112. The auxiliary winding generates
voltage in a fourth pulsating waveform based on the voltage with
the first pulsating waveform that is modulated. The power supply
circuit 112 is connected to the auxiliary winding. The power supply
circuit 112 (for example, including a filter regulator module, a
voltage conversion module, etc.) is configured to convert the
voltage in the fourth pulsating waveform to output DC power so as
to supply power to the drive circuit 110 and/or the control circuit
107. The power supply circuit 112 may be constituted by elements,
such as a small filter capacitor, a voltage regulator chip, etc.,
to process and convert the voltage in the fourth pulsating
waveform, thus outputting a low voltage DC power, such as 3.3V, or
5V, etc.
[0178] In other words, a power supply of the drive circuit 110 can
be obtained through converting the voltage in the fourth pulsating
waveform by the power supply circuit 112. When the control circuit
107 is disposed on the primary side, a power supply of the control
circuit 107 can be obtained through converting the voltage in the
fourth pulsating waveform by the power supply circuit 112. As shown
in FIG. 9, when the control circuit 107 is disposed on the primary
side, the power supply circuit 112 provides a two-way DC output to
respectively supply power to the drive circuit 110 and the control
circuit 107. The isolation circuit 111, e.g. an optocoupler, is
disposed between the control circuit 107 and the sampling circuit
106 to achieve the signal isolation between the primary side and
the secondary side of the power adapter 1.
[0179] When the control circuit 107 is disposed on the primary side
and is integrated with the drive circuit 110, the power supply
circuit 112 only supplies power to the control circuit 107. When
the control circuit 107 is disposed on the secondary side and the
drive circuit 110 is disposed on the primary side, the power supply
circuit 112 only supplies power to the drive circuit 110. The power
of the control circuit 107 is supplied by the secondary side, for
example, a power supply circuit is used to convert the voltage with
the third pulsating waveform output from the second rectifying
circuit 104 to a DC power so as to supply power to the control
circuit 107.
[0180] In one embodiment of the present disclosure, output
terminals of the first rectifying circuit 101 are further connected
in parallel with a plurality of small capacitors to have a
filtering effect. Or, the output terminals of the first rectifying
circuit 101 are connected to an LC filter circuit.
[0181] In another embodiment of the present disclosure, the power
adapter 1 further includes a first voltage detection circuit 113 as
shown in FIG. 10. The first voltage detection circuit 113 is
connected to the auxiliary winding and the control circuit 107. The
first voltage detection circuit 113 is configured to detect the
voltage in the fourth pulsating waveform to generate a voltage
detection value. The control circuit 107 is further configured to
modulate a duty cycle of a control signal based on the voltage
detection value.
[0182] In other words, the control circuit 107 can reflect voltage
output from the second rectifying circuit 104 based on voltage
output from the auxiliary winding detected by the voltage detection
circuit 113, and then modulate the duty cycle of the control signal
based on the voltage detection value, so that the output of the
second rectifying circuit 104 matches the charging requirement of
the battery.
[0183] In greater detail, in one embodiment of the present
disclosure, the sampling circuit 106 includes a first current
sampling circuit 1061 and a first voltage sampling circuit 1062 as
shown in FIG. 11. The first current sampling circuit 1061 is
configured to sample a current output from the second rectifying
circuit 104 to obtain a current sampling value. The voltage
sampling circuit 1062 is configured to sample voltage output from
the second rectifying circuit 104 to obtain voltage sampling
value.
[0184] Optionally, the first current sampling circuit 1061 can
sample voltage across a resistor (current sensing resistor)
connected to the first output terminal of the second rectifying
circuit 104 to achieve the sampling of the current output from the
second rectifying circuit 104. The first voltage sampling circuit
1062 can sample voltage between the first output terminal and a
second output terminal of the second rectifying circuit 104 to
achieve the sampling of the voltage output from the second
rectifying circuit 104.
[0185] In one embodiment of the present disclosure, the first
voltage sampling circuit 1062 includes a peak voltage sampling and
retaining circuit, a zero-crossing sampling circuit, a discharge
circuit, and an analog/digital (AD) sampling circuit as shown in
FIG. 11. The peak voltage sampling and retaining circuit is
configured to sample and retain a peak voltage of the voltage with
the third pulsating waveform. The zero-crossing sampling circuit is
configured to sample zero-crossing points of the voltage with the
third pulsating waveform. The discharge circuit is configured to
discharge the peak voltage sampling and retaining circuit at the
zero-crossing points. The AD sampling circuit is configured to
sample the peak voltage in the peak voltage sampling and retaining
circuit so as to obtain the voltage sampling value.
[0186] Through disposing the peak voltage sampling and retaining
circuit, the zero-crossing sampling circuit, the discharge circuit,
and the AD sampling circuit in the first voltage sampling circuit
1062, accurate sampling of the voltage output from the second
rectifying circuit 104 can be achieved. In addition, the voltage
sampling value can be ensured to be synchronized with the voltage
with the first pulsating waveform, that is, the phases are
synchronous and the amplitude change trends are consistent.
[0187] According to one embodiment of the present disclosure, the
power adapter 1 further includes a second voltage sampling circuit
114 as shown in FIG. 12. The second voltage sampling circuit 114 is
configured to sample the voltage with the first pulsating waveform.
The second voltage sampling circuit 114 is connected to the control
circuit 107. When a voltage value sampled by the second voltage
sampling circuit 114 is greater than a first predetermined voltage
value, the control circuit 107 controls the switch circuit 102 to
turn on for a first predetermined time so as to discharge a surge
voltage, a spike voltage, etc. with the first pulsating
waveform.
[0188] As shown in FIG. 12, the second voltage sampling circuit 114
may be connected to a first output terminal and a second output
terminal of the first rectifying circuit 101 to achieve the
sampling of the voltage with the first pulsating waveform. The
control circuit 107 makes a judgment on the voltage value sampled
by the second voltage sampling circuit 114. If the voltage value
sampled by the second voltage sampling circuit 114 is greater than
the first predetermined voltage value, the power adapter 1 is
interfered with by a lighting stroke so the surge voltage appears.
At This time, the surge voltage needs to be discharged to ensure
the safety and reliability of charging. The control circuit 107
controls the switch circuit 102 to turn on for a period of time to
form a discharge path. The surge voltage caused by the lighting
stroke is discharged to prevent interference caused by the lighting
stroke when the power adapter charges the terminal. As a result,
the safety and reliability of charging the terminal is effectively
improved. The first predetermined voltage value may be set
depending on practical situations.
[0189] In one embodiment of the present disclosure, during the
process that the power adapter charges the battery 202 of the
terminal 2, the control circuit 107 is further configured to
control the switch circuit 102 to turn off when a voltage value
sampled by the sampling circuit 106 is greater than a second
predetermined voltage value. That is, the control circuit 107
further makes a judgment on a magnitude of the voltage value
sampled by the sampling circuit 106. If the voltage value sampled
by the sampling circuit 106 is greater than a second predetermined
voltage value, voltage output from the power adapter 1 is
excessively high. At this time, the control circuit 107 controls
the switch circuit 102 to turn off so that the power adapter 1
stops charging the battery 202 of the terminal 2. In other words,
the control circuit 107 achieves the overvoltage protection of the
power adapter 1 through controlling the switch circuit 102 to turn
off so as to ensure safe charging.
[0190] In one embodiment of the present disclosure, the controller
204 performs the bidirectional communication with the control
circuit 107 to acquire the voltage value sampled by the sampling
circuit 106 (see FIG. 13 and FIG. 14), and controls the charging
control switch 203 to turn off when the voltage value sampled by
the sampling circuit 106 is greater than the second predetermined
voltage value. That is, the charging control switch 203 is turned
off through a side of the terminal 2 so as to turn off the charging
process of the battery 202. The charging safety is ensured.
[0191] In addition, the control circuit 107 is further configured
to control the switch circuit 102 to turn off when a current value
sampled by the sampling circuit 106 is greater than a predetermined
current value. That is, the control circuit 107 further makes a
judgment on a magnitude of the current value sampled by the
sampling circuit 106. If the current value sampled by the sampling
circuit 106 is greater than the predetermined current value, a
current output from the power adapter 1 is excessively high. At
this time, the control circuit 107 controls the switch circuit 102
to turn off so that the power adapter 1 stops charging the terminal
2. In other words, the control circuit 107 achieves the overcurrent
protection of the power adapter 1 through controlling the switch
circuit 102 to turn off so as to ensure safe charging.
[0192] Similarly, the controller 204 performs the bidirectional
communication with the control circuit 107 to acquire the current
value sampled by the sampling circuit 106 (see FIG. 13 and FIG.
14), and controls the charging control switch 203 to turn off when
the current value sampled by the sampling circuit 106 is greater
than the predetermined current value. That is, the charging control
switch 203 is turned off through the side of the terminal 2 so as
to turn off the charging process of the battery 202. The charging
safety is ensured.
[0193] Both the second predetermined voltage value and the
predetermined current value may be set or written to a memory of
the control circuit (for example, in the control circuit 107 of the
power adapter 1, such as a micro controller unit (MCU)) depending
on practical situations.
[0194] In one embodiment of the present disclosure, the terminal
may be a mobile terminal, such as a cellphone, a mobile power
supply, such as a charging bank, a multimedia player, a notebook
computer, or a wearable device, etc.
[0195] According to the embodiment of the present disclosure, the
charging system for the terminal controls the power adapter to
output the voltage with the third pulsating waveform, and directly
applies the voltage with the third pulsating waveform output from
the power adapter to the battery in the terminal, so that the fast
charging of the battery directly by the output voltage/current that
is pulsating can be achieved. A magnitude of the output
voltage/current that is pulsating changes periodically. As compared
with the disclosures of charging with constant voltage and constant
current in the related art, the lithium precipitation phenomenon of
the lithium battery can be reduced. The service life of the battery
can be improved. In addition, the probability of arcing and the
force of the contact at the charging interface can further be
reduced to improve the life of the charging interface. It is also
advantageous in reducing the polarization effect of the battery,
improving the charging speed, reducing the battery heat so as to
ensure the safety and reliability when the terminal is charged.
Additionally, because the power adapter outputs the voltage with
the pulsating waveform, there is no necessity to dispose
electrolytic capacitors in the power supply adapter. Not only can
the power adapter simplified and miniaturized, but the cost can
also be greatly reduced. Additionally, two current sampling modes
are alternatively switched to sample the current, which ensures the
sensing function with the compatibility between sensing precision
and dynamic range and expands the scope of the applications.
[0196] In addition, the present disclosure also provides a power
adapter. The power adapter includes a first rectifying circuit
configured to rectify an alternating current to voltage with a
first pulsating waveform, a switch circuit configured to modulate
the voltage with the first pulsating waveform according to a
control signal, a transformer configured to output voltage with a
second pulsating waveform according to the modulated voltage with
the first pulsating waveform, a second rectifying circuit
configured to rectify the voltage with the second pulsating
waveform to voltage in a third pulsating waveform, a first charging
interface coupled to the second rectifying circuit, a first current
sampling circuit configured to sample current outputted by the
second rectifying circuit to obtain a current sampling value, the
first current sampling circuit selectively operable in a first
current sampling mode and a second current sampling mode, a mode
switch circuit configured to control the first current sampling
circuit to switch between the first current sampling mode and the
second current sampling mode, and a control circuit coupled to the
first current sampling circuit, the mode switch circuit, and the
mode switch circuit. The control circuit is configured to output
the control signal to the switch circuit, configured to control the
mode switch circuit to control the first current sampling circuit
operating in the first current sampling mode or the second current
sampling mode based on a charging mode, and configured to regulate
a duty cycle of the control signal according to the current
sampling value so that the voltage with the third pulsating
waveform satisfies a requirement of charging. The first charging
interface is configured to apply the voltage with the third
pulsating waveform to a battery of a terminal through a second
charging interface of the terminal when the second charging
interface of the terminal couples to the first charging interface.
The battery is coupled to the second charging interface.
[0197] According to the embodiment of the present disclosure, the
power adapter outputs the voltage with the third pulsating waveform
through the first charging interface, and directly applies the
voltage with the third pulsating waveform output from the power
adapter to the battery through the second charging interface in the
terminal, so that the fast charging of the battery directly by the
output voltage/current that is pulsating can be achieved. A
magnitude of the output voltage/current that is pulsating changes
periodically. As compared with the disclosures of charging with
constant voltage and constant current in the related art, the
lithium precipitation phenomenon of the lithium battery can be
reduced. The service life of the battery can be improved. In
addition, the probability of arcing and the force of the contact at
the charging interface can further be reduced to improve the life
of the charging interface. It is also advantageous in reducing the
polarization effect of the battery, improving the charging speed,
reducing the battery heat so as to ensure the safety and
reliability when the terminal is charged. Additionally, because the
power adapter outputs the voltage with the pulsating waveform,
there is no necessity to dispose electrolytic capacitors in the
power supply adapter. Not only can the power adapter simplified and
miniaturized, but the cost can also be greatly reduced.
Additionally, two current sampling modes are alternatively switched
to sample the current, which ensures the sensing function with the
compatibility between sensing precision and dynamic range and
expands the scope of the applications.
[0198] FIG. 15 illustrates a flowchart of a charging method for a
terminal according to one embodiment of the present disclosure. As
shown in FIG. 15, the charging method for the terminal can begin at
block S1.
[0199] At block S1, an AC power input to a power adapter is
rectified for the first time to output voltage with a first
pulsating waveform when a first charging interface of the power
adapter is connected to a second charging interface of a
terminal.
[0200] That is, a first rectifying circuit in the power adapter is
used to rectify AC mains of an input AC power (that is, mains, such
as 220V, 50 Hz or 60 Hz) and output voltage in a clipped pulsating
waveform of the voltage with the first pulsating waveform (such as
100 Hz or 120 Hz).
[0201] At block S2, a switch circuit is controlled to modulate the
voltage with the first pulsating waveform, and voltage with a
second pulsating waveform is output through transformation of a
transformer.
[0202] The switch circuit may be constituted by a MOS transistor. A
peak clipping modulation is performed to the voltage in the clipped
pulsating waveform through performing a PWM control to the MOS
transistor. Then, the voltage with the first pulsating waveform
thus modulated is coupled to a secondary side by the transformer,
and the voltage with the second pulsating waveform is output by a
secondary winding.
[0203] In one embodiment of the present disclosure, a
high-frequency transformer may be adopted to perform
transformation. In this manner, a size of the transformer can be
very small, thus being able to achieve a high-power and small-sized
design of the power adapter.
[0204] At block S3, the voltage with the second pulsating waveform
is rectified for the second time to output voltage in a third
pulsating waveform. The voltage with the third pulsating waveform
can be applied to a battery of the terminal through the second
charging interface to achieve the charging of the battery of the
terminal.
[0205] In one embodiment of the present disclosure, the voltage
with the second pulsating waveform is rectified for the second time
through a second rectifying circuit. The second rectifying circuit
may be constituted by a diode or a MOS transistor to achieve
secondary synchronous rectification so that the modulated first
pulsating waveform is synchronized with the third pulsating
waveform.
[0206] At block S4, current corresponding to the voltage with the
third pulsating waveform is sampled to obtain a current sampling
value. The first current sampling circuit is selectively operable
in a first current sampling mode and a second current sampling
mode.
[0207] At block S5, the first current sampling circuit is
controlled to operate in the first current sampling mode or the
second current sampling mode according to a charging mode, while a
duty cycle of the control signal applied to the switch circuit is
modulated based on the current sampling value so that the voltage
with the third pulsating waveform satisfies the charging
requirement.
[0208] According to another embodiment of the present disclosure, a
frequency of the control signal is regulated according to the
current sampling value.
[0209] According to another embodiment of the present disclosure,
voltage and/or current being rectified twice can be sampled to
obtain a voltage sampling value and/or a current sampling value. A
duty cycle of the control signal applied to the switch circuit can
be modulated based on the voltage sampling value and/or the current
sampling value so that the voltage with the third pulsating
waveform satisfies the charging requirement.
[0210] It is noted that the voltage with the third pulsating
waveform satisfying the charging requirement refers to that the
voltage and a current with the third pulsating waveform satisfy a
charging voltage and a charging current when the battery is
charged. That is, the duty cycle of the control signal, such as a
PWM signal, can be modulated based on voltage and/or current output
from the power adapter thus sampled to adjust an output of the
power adapter in a real-time manner. A closed-loop regulation
control is thus realized so that the voltage in the third pulsation
waveform satisfies the charging requirement of the terminal to
ensure that the battery is safely and reliably charged. The
charging voltage waveform output to the battery being regulated
through the duty cycle of the PWM signal is shown in FIG. 3. The
charging current waveform output to the battery being regulated
through the duty cycle of the PWM signal is shown in FIG. 4.
[0211] Hence, according to the embodiment of the present
disclosure, the voltage in the first pulsation waveform, that is,
the voltage in the clipped pulsating waveform, which is rectified
by a full bridge is directly modulated by performing PWM peak
clipping through controlling the switch circuit, and delivered to
the high-frequency transformer to be coupled from a primary side to
the secondary side through the high-frequency transformer, and then
be recovered as the voltage/current in the clipped pulsating
waveform through synchronous rectification to be directly delivered
to the battery of the terminal so as to achieve the fast charging
of the battery. An amplitude of the voltage in the clipped
pulsating waveform can be regulated through adjusting the duty
cycle of the PWM signal. As a result, the output of the power
adapter satisfies the charging requirement of the battery. It can
be seen that the electrolytic capacitors on the primary side and
the secondary side in the power adapter can be removed. Through
using the voltage in the clipped pulsating waveform to directly
charge the battery, the size of the power adapter can be reduced to
miniaturize the power adapter and significantly reduce the
cost.
[0212] According to one embodiment of the present disclosure, the
first current sampling circuit is controlled to operate in the
first current sampling mode, when a bidirectional communication
between the terminal and the power adapter via the first charging
interface is established to determine that the terminal is charged
by the first charging mode. The first current sampling circuit is
controlled to operate in the second current sampling mode, when the
bidirectional communication between the terminal and the power
adapter via the first charging interface is established to
determine that the terminal is charged by the second charging
mode.
[0213] According to one embodiment of the present disclosure, a
frequency of the control signal is modulated based on the voltage
sampling value and/or the current sampling value. The PWM signal
output to the switch circuit can thus be controlled to be
continuously output for a period of time and then be stopped. After
the output has been stopped for a predetermined time, the output of
the PWM is turned on again. In this manner, the voltage applied to
the battery is intermittent and the battery is intermittently
charged. As a result, the security worry caused by serious heating
when the battery is continuously charged can be avoided to improve
the reliability and safety of battery charging. The control signal
output to the switch circuit may be shown in FIG. 5.
[0214] In addition to that, the charging method for the terminal
further includes: state information of the terminal is acquired
through a communication between the first charging interface and
the terminal so as to modulate the duty cycle of the control signal
based on the state information of the terminal, and/or the voltage
sampling value and/or the current sampling value.
[0215] In other words, when the second charging interface is
connected to the first charging interface, the power adapter and
the terminal can send a communication inquiry instruction to each
other, and establish a communication connection between the power
adapter and the terminal after receiving a reply instruction
correspondingly. In this manner, the state information of the
terminal can be acquired so that the power adapter negotiates a
charging mode and charging parameters (such as the charging
current, the charging voltage) with the terminal and controls the
charging process.
[0216] According to one embodiment of the present disclosure,
voltage in a fourth pulsating waveform is generated through
transformation of the transformer, and the voltage in the fourth
pulsating waveform is detected to generate a voltage detection
value so as to modulate the duty cycle of the control signal based
on the voltage detection value.
[0217] In greater detail, an auxiliary winding may be further
disposed in the transformer. The auxiliary winding can generate the
voltage in the fourth pulsating waveform based on the modulated
first pulsating waveform. In this manner, an output voltage of the
power adapter can be reflected through detecting the voltage in the
fourth pulsating waveform so as to modulate the duty cycle of the
control signal based on the voltage detection value. As a result,
the output of the power adapter matches the charging requirement of
the battery.
[0218] In one embodiment of the present disclosure, sampling the
voltage that has been rectified twice to obtain the voltage
sampling value includes: a peak voltage of the voltage that has
been rectified twice is sampled and retained and zero-crossing
points of the voltage that has been rectified twice are sampled; a
peak voltage sampling and retaining circuit that samples and
retains the peak voltage is discharged at the zero-crossing points;
the peak voltage in the peak voltage sampling and retaining circuit
is sampled to obtained the voltage sampling value. Hence, accurate
sampling of the voltage output from the power adapter can be
achieved. In addition, the voltage sampling value can be ensured to
be synchronized with the voltage with the first pulsating waveform,
that is, the phases the amplitude change trends are consistent.
[0219] Moreover, in one embodiment of the present disclosure, the
charging method for the terminal further includes: the voltage with
the first pulsating waveform is sampled and the switch circuit is
controlled to turned on for a first predetermined time to discharge
a surge voltage with the first pulsating waveform when a voltage
value thus sampled is greater than a first predetermined voltage
value.
[0220] Through sampling the voltage with the first pulsating
waveform and then making a judgment on a sampled voltage value, the
power adapter is interfered with by a lighting stroke so the surge
voltage appears if the sampled voltage value is greater than the
first predetermined voltage value. At this time, the surge voltage
needs to be discharged to ensure the safety and reliability of
charging. The switch circuit needs to be controlled to turn on for
a period of time to form a discharge path. The surge voltage caused
by the lighting stroke is discharged to prevent interference caused
by the lighting stroke when the power adapter charges the terminal.
As a result, the safety and reliability of charging the terminal is
effectively improved. The first predetermined voltage value may be
set depending on practical situations.
[0221] According to one embodiment of the present disclosure, the
charging mode is further determined through a communication between
the first charging interface and the terminal, and a charging
current and/or a charging voltage corresponding to a first charging
mode is obtained based on the state information of the terminal
when the charging mode is determined to be the first charging mode.
The duty cycle of the control signal is thus modulated based on the
charging current and/or the charging voltage corresponding to the
first charging mode. The charging mode includes the first charging
mode and a second charging mode.
[0222] In other words, when a current charging mode is determined
to be the first charging mode, the charging current and/or the
charging voltage corresponding to the first charging mode can he
obtained based on acquired state information of the terminal, such
as a battery voltage, a battery level, a battery temperature,
operating parameters of the terminal, and power consumption
information of an application running on the terminal, etc. Then,
the duty cycle of the control signal is modulated based on the
obtained charging current and/or charging voltage. As a result, the
output of the power adapter satisfies the charging requirement to
achieve the fast charging of the battery.
[0223] The state information of the terminal includes the battery
temperature. In addition, when the battery temperature is higher
than a first predetermined threshold temperature or lower than a
second predetermined threshold temperature, the first charging mode
is switched to the second charging mode if the current charging
mode is the first charging mode. The first predetermined threshold
temperature is higher the second predetermined threshold
temperature. In other words, when the battery temperature is
excessively low (for example, the battery temperature is lower than
the second predetermined threshold temperature) or excessively high
(for example, the battery temperature is higher than the first
predetermined threshold temperature), neither is suitable for fast
charging. Therefore, the first charging mode needs to be switched
to the second charging mode. In the embodiment of the present
disclosure, the first predetermined threshold temperature and the
second predetermined threshold temperature may be set depending on
practical situations.
[0224] In one embodiment of the present disclosure, the switch
circuit is controlled to turn off when the battery temperature is
higher than a high temperature protection threshold that is
predetermined. That is, a high temperature protection strategy
needs to be adopted to control the switch circuit to turn off when
the battery temperature exceeds the high temperature protection
threshold, so that the power adapter stops charging the battery.
The high temperature protection of battery is thus achieved to
improve charging safety. The high temperature protection threshold
may be different from the first predetermined threshold
temperature, or may be the same as the first predetermined
threshold temperature. In at least one embodiment, the high
temperature protection threshold is higher than the first
predetermined threshold temperature.
[0225] In another embodiment of the present disclosure, the
terminal further acquires the battery temperature, and controls the
battery by stopping the charging when the battery temperature is
higher than the high temperature protection threshold that is
predetermined. That is, a charging control switch can be turned off
through a terminal side to end the charging process of the battery
so as to ensure charging safety.
[0226] In one embodiment of the present disclosure, the charging
method for the terminal further includes: a temperature of the
first charging interface is acquired, and the switch circuit is
controlled to turned off when the temperature of the first charging
interface is higher than a predetermined protection temperature.
That is, the control circuit also needs to execute the high
temperature protection strategy to control the switch circuit to
turn off when the temperature of the first charging interface
exceeds a certain temperature, so that the power adapter stops
charging the battery. The high temperature protection of charging
interface is thus achieved to improve the charging safety.
[0227] In another embodiment of the present disclosure, the
terminal acquires the temperature of the first charging interface
by performing a bidirectional communication with the power adapter
through the second charging interface, and controls the battery by
stopping the charging when the temperature of the first charging
interface is higher than the predetermined protection temperature.
That is, the charging control switch can be turned off through the
terminal side to end the charging process of the battery so as to
ensure charging safety.
[0228] During the process that the power adapter charges the
terminal, the switch circuit is controlled to turn off when the
voltage sampling value is greater than a second predetermined
voltage value. That is, during the process that the power adapter
charges the terminal, a judgment is further made on a magnitude of
the voltage sampling value. If the voltage sampling value is
greater than the second predetermined voltage value, the voltage
output from the power adapter is excessively high. At this time,
the switch circuit is controlled to turn off so that the power
adapter stops charging the terminal. In other words, the
overvoltage protection of the power adapter is achieved through
controlling the switch circuit to turn off so as to ensure safe
charging.
[0229] In one embodiment of the present disclosure, the terminal
acquires the voltage sampling value by performing the bidirectional
communication with the power adapter through the second charging
interface, and controls the battery by stopping the charging when
the voltage sampling value is greater than the second predetermined
voltage value. That is, the charging control switch can be turned
off through the terminal side so as to end the charging process of
the battery. The charging safety is ensured.
[0230] In one embodiment of the present disclosure, during the
process that the power adapter charges the terminal, the switch
circuit is controlled to turn off when the current sampling value
is greater than a predetermined current value. That is, during the
process that the power adapter charges the terminal, a judgment is
further made on a magnitude of the current sampling value. If the
current sampling value is greater than the predetermined current
value, the current output from the power adapter is excessively
high. At this time, the switch circuit is controlled to turn off so
that the power adapter stops charging the terminal. In other words,
the overcurrent protection of the power adapter is achieved through
controlling the switch circuit to turn off so as to ensure safe
charging.
[0231] Similarly, the terminal acquires the current sampling value
by performing the bidirectional communication with the power
adapter through the second charging interface, and controls the
battery by stopping the charging when the current sampling value is
greater than the predetermined current value. That is, the charging
control switch can be turned off through the terminal side so as to
end the charging process of the battery. The charging safety is
ensured.
[0232] Both the second predetermined voltage value and the
predetermined current value may be set depending on practical
situations.
[0233] In one embodiment of the present disclosure, the state
information of the terminal comprises a battery level, a battery
temperature, voltage/current of the terminal, interface information
of the terminal, or path impedance information of the terminal.
[0234] In greater detail, the power adapter and the terminal are
connected through a universal serial bus (USB) interface. The USB
interface may be a normal USB interface, or may be a micro USB
interface. Data lines in the USB interface are the data lines in
the first charging interface and are configured to provide a
bidirectional communication between the power adapter and the
terminal. The data lines may be a D+ line and/or a D- line in the
USB interface, and the bidirectional communication can refer to the
information exchange between the power adapter and the
terminal.
[0235] The power adapter performs the bidirectional communication
with the terminal through the data lines in the USB interface to
determine that the terminal is charged by the first charging
mode.
[0236] Optionally, in some embodiments, when a bidirectional
communication between the terminal and the first charging interface
is established to determine that the terminal is charged by the
first charging mode, a first instruction, configured to inquire of
the terminal whether to enable the first charging mode or not, is
sent to the terminal by the power adapter, and a reply instruction
responsive to the first instruction from the terminal, configured
to indicate that the terminal agrees to enable the first charging
mode, is received by the power adapter.
[0237] Optionally, in some embodiments, before sending the first
instruction to the terminal, the power adapter charges the terminal
through the second charging mode, the first instruction is sent to
the terminal if a charging time of the second charging mode is
longer than a predetermined threshold value.
[0238] It is noted that if a charging time of the second charging
mode is longer than a predetermined threshold value, the power
adapter determines that the terminal has identified the power
adapter and can enable fast charging inquiry.
[0239] Optionally, in some embodiments, before a charging current
of the power adapter is adjusted to a charging current
corresponding to the first charging mode by controlling the switch
circuit, and the power adapter uses the charging current
corresponding to the first charging mode to charge the terminal, a
charging voltage corresponding to the first charging mode is
determined through the bidirectional communication between the
terminal and the power adapter via the first charging interface.
The power adapter is controlled to adjust a charging voltage to the
charging voltage corresponding to the first charging mode.
[0240] Optionally, in some embodiments, the determining a charging
voltage corresponding to the first charging mode through the
bidirectional communication between the terminal and the power
adapter via the first charging interface includes: a second
instruction that is configured to inquire whether or not a current
output voltage of the power adapter is suitable as a charging
voltage of the first charging mode is sent to the terminal by the
power adapter, and a reply instruction responsive to the second
instruction sent by the terminal is received by the power adapter.
The reply instruction responsive to the second instruction is
configured to indicate that the current output voltage of the power
adapter is suitable, excessively high, or excessively low. Then the
charging voltage of the first charging mode is determined by the
power adapter based on the reply instruction responsive to the
second instruction.
[0241] Optionally, in some embodiments, before the charging current
of the power adapter is adjusted to the charging current
corresponding to the first charging mode, the charging current
corresponding to the first charging mode is determined through the
bidirectional communication between the terminal and the power
adapter via the first charging interface.
[0242] Optionally, in some embodiments, the determining the
charging current corresponding to the first charging mode through
the bidirectional communication between the terminal and the power
adapter via the first charging interface includes: a third
instruction to the terminal is sent by the power adapter, a reply
instruction responsive to the third instruction sent by the
terminal is received by the power adapter, and a charging current
of the first charging mode is determined based on the reply
instruction responsive to the third instruction. The third
instruction is configured to inquire about a maximum charging
current currently supported by the terminal. The reply instruction
responsive to the third instruction configured to indicate the
maximum charging current currently supported by the terminal.
[0243] The power adapter can set the maximum charging current as
the charging current of the first charging mode, or any charging
current less than maximum charging current as the charging current
of the first charging mode.
[0244] Optionally, in some embodiments, during the process that the
power adapter is operable in the first charging mode to charge the
terminal, the charging current output to the battery from the power
adapter is continuously adjusted by controlling the switch circuit
through the bidirectional communication between the terminal and
the power adapter via the first charging interface.
[0245] The power adapter can continuously inquiry the current state
information of the terminal, such as battery voltage or power
volume of the battery, so as to continuously adjust the charging
current.
[0246] Optionally, in some embodiments, the continuously adjusting
the charging current output to the battery from the power adapter
through controlling the switch circuit through the bidirectional
communication between the terminal and the power adapter via the
first charging interface, includes: a fourth instruction to the
terminal is sent by the power adapter, a reply instruction
responsive to the fourth instruction sent from the terminal is
received by the power adapter, and the charging current is adjusted
through controlling the switch circuit based on the current voltage
of the battery. The fourth instruction is configured to inquire
about a current voltage of the battery in the terminal. The reply
instruction responsive to the fourth instruction configured to
indicate the current voltage of the battery in the terminal.
[0247] Optionally, in some embodiments, the adjusting the charging
current through controlling the switch circuit based on the current
voltage of the battery, includes: the charging current output to
the battery from the power adapter is adjusted to a charging
current value corresponding to the current voltage of the battery
through controlling the switch circuit based on the current voltage
of the battery and a predetermined relationship between a battery
voltage value and a charging current value.
[0248] Optionally, the power adapter can store a relationship
between the battery voltage and charging current.
[0249] Optionally, in some embodiments, during the process that the
power adapter is operable in the first charging mode to charge the
terminal, it is determined that whether there is a bad contact
between the first charging interface and a second charging
interface or not, through the bidirectional communication between
the terminal and the power adapter via the first charging
interface. The power adapter is controlled to exit the first
charging mode when it is determined that there is a bad contact
between the first charging interface and the second charging
interface.
[0250] Optionally, in some embodiments, before determining whether
there is a bad contact between the first charging interface and the
second charging interface or not, an information indicative of a
path impedance of the terminal from the terminal is received. The
receiving information indicative of a path impedance of the
terminal from the terminal includes: a fourth instruction to the
terminal is sent by the power adapter, a reply instruction
responsive to the fourth instruction sent by the terminal is
received by the power adapter, a path impedance from the power
adapter to the battery is determined based on an output voltage of
the power adapter and the voltage of the battery, and it is
determined whether there is a bad contact between the first
charging interface and the second charging interface or not based
on the path impedance from the power adapter to the battery, the
path impedance of the terminal, and a path impedance of charging
lines between the power adapter and the terminal. The fourth
instruction is configured to inquire about voltage of the battery
in the terminal. The reply instruction responsive to the fourth
instruction is configured to indicate the voltage of the battery in
the terminal.
[0251] Optionally, in some embodiments, before the power adapter is
controlled to exit the first charging mode, a fifth instruction is
sent to the terminal. The fifth instruction is configured to
indicate that there is a bad contact between the first charging
interface and the second charging interface.
[0252] After sending the fifth instruction, the power adapter can
exit rapidly and reset.
[0253] The description of fast charging process in the above
paragraphs is in view of the power adapter. The following describes
the fast charging process in view of the terminal.
[0254] According to the present disclosure, the terminal supports
the second charging mode and the first charging mode. A charging
current of the first charging mode is greater than a charging
current of the second charging mode. The power adapter determines
that the first charging mode is used to charge the terminal,
through the bidirectional communication between the second charging
interface of the terminal and the adapter. The power adapter
outputs the charging current corresponding to the first charging
mode to charge the battery in the terminal.
[0255] Optionally, in some embodiments, determining that the first
charging mode is used to charge the terminal, through the
bidirectional communication between the second charging interface
of the terminal and the adapter, includes: the terminal receives a
first instruction sent from the power adapter, the first
instruction configured to inquire of the terminal whether to enable
the first charging mode or not; the terminal sends a reply
instruction responsive to the first instruction to the power
adapter, the reply instruction responsive to the first instruction
configured to indicate that the terminal agrees to enable the first
charging mode.
[0256] Optionally, in some embodiments, before receiving the first
instruction sent from the power adapter, the power adapter charges
the terminal through the second charging mode. The terminal
receives the first instruction sent from the power adapter if a
charging time of the second charging mode is longer than a
predetermined threshold value.
[0257] Optionally, in some embodiments, before a charging current
of the power adapter is adjusted to a charging current
corresponding to the first charging mode, and the power adapter
uses the charging current corresponding to the first charging mode
to charge the terminal, the charging voltage corresponding to the
first charging mode is determined through the bidirectional
communication between the power adapter and the second charging
interface of the terminal.
[0258] Optionally, in some embodiments, determining the charging
voltage corresponding to the first charging mode through the
bidirectional communication between the power adapter and the
second charging interface of the terminal, includes: the terminal
receives a second instruction sent by the power adapter, the second
instruction configured to inquire whether or not a current output
voltage of the power adapter is suitable as a charging voltage of
the first charging mode; the terminal sends a reply instruction
responsive to the second instruction to the power adapter, the
reply instruction responsive to the second instruction configured
to indicate that the current output voltage of the power adapter is
suitable, excessively high, or excessively low.
[0259] Optionally, in some embodiments, before the charging current
of the power adapter is adjusted to the charging current
corresponding to the first charging mode, and the terminal uses the
charging current corresponding to the first charging mode to charge
the battery, the power adapter determines the charging current
corresponding to the first charging mode through the bidirectional
communication between the power adapter and the second charging
interface of the terminal.
[0260] Optionally, in some embodiments, the power adapter
determines the charging current corresponding to the first charging
mode through the bidirectional communication between the power
adapter and the second charging interface of the terminal,
includes: the terminal receives a third instruction sent by the
power adapter, the third instruction configured to inquire about a
maximum charging current currently supported by the terminal; the
terminal sends a reply instruction responsive to the third
instruction to the power adapter, the reply instruction responsive
to the third instruction configured to indicate the maximum
charging current currently supported by the terminal to allow the
power adapter to determine the charging current corresponding to
the first charging mode based on the maximum charging current.
[0261] Optionally, in some embodiments, during the process that the
power adapter is operable in the first charging mode to charge the
terminal, the power adapter continuously adjusts the charging
current output to the battery from the power adapter through the
bidirectional communication between the terminal and the power
adapter via the first charging interface.
[0262] Optionally, in some embodiments, continuously adjusting the
charging current output to the battery from the power adapter
through the bidirectional communication between the terminal and
the power adapter via the first charging interface, includes: the
terminal receives a fourth instruction sent by the power adapter,
the fourth instruction configured to inquire about a current
voltage of the battery in the terminal; the terminal sends a reply
instruction responsive to the fourth instruction to the power
adapter, the reply instruction responsive to the fourth instruction
configured to indicate the current voltage of the battery in the
terminal to allow the power adapter to continuously adjust the
charging current output to the battery from the power adapter based
on the current voltage of the battery.
[0263] Optionally, in some embodiments, during the process that the
power adapter is operable in the first charging mode to charge the
terminal, the power adapter determines whether there is a bad
contact between the first charging interface and the second
charging interface or not through the bidirectional communication
between the second charging interface and the power adapter.
[0264] Optionally, in some embodiments, determining whether there
is a bad contact between the first charging interface and the
second charging interface or not through the bidirectional
communication between the second charging interface and the power
adapter, includes: the terminal receives a fourth instruction sent
by the power adapter, the fourth instruction configured to inquire
about a current voltage of the battery in the terminal; the
terminal sends a reply instruction responsive to the fourth
instruction to the control circuit, the reply instruction
responsive to the fourth instruction configured to indicate the
current voltage of the battery in the terminal to allow the power
adapter to determine whether there is a bad contact between the
first charging interface and the second charging interface or not
based on the output voltage of the power adapter and the current
voltage of the battery.
[0265] Optionally, in some embodiments, the terminal receives a
fifth instruction sent by the power adapter. The fifth instruction
is configured to indicate that there is a bad contact between the
first charging interface and the second charging interface.
[0266] In order to enable the first charging mode, the power
adapter can perform a fast charging communication process with the
terminal. Through one or more handshake negotiations, the fast
charging of the battery is achieved. A detailed description of the
fast charging communication process and various stages of the fast
charging process according to the embodiment of the present
disclosure is provided as follows with reference to FIG. 6. It
should be understood that the communication steps or operations
shown in FIG. 6 are merely examples, and the embodiment of the
present disclosure may further perform other operations or
variations of the various operations in FIG. 6. In addition, the
various stages in FIG. 6 may be performed in an order different
from that presented in FIG. 6, and it may not be necessary to
perform all the operations in FIG. 6.
[0267] In summary, according to the embodiment of the present
disclosure, the charging method for the terminal controls the power
adapter to output the voltage with the third pulsating waveform
that satisfies the charging requirement, and directly applies the
voltage with the third pulsating waveform output from the power
adapter to the battery in the terminal, so that the fast charging
of the battery directly by the output voltage/current that is
pulsating can be achieved. A magnitude of the output
voltage/current that is pulsating changes periodically. As compared
with the disclosure of charging with constant voltage and constant
current in the related art, the lithium precipitation phenomenon of
the lithium battery can be reduced. The service life of the battery
can be improved. In addition, the probability of arcing and the
force of the contact at the charging interface can further be
reduced to improve the life of the charging interface. It is also
advantageous in reducing the polarization effect of the battery,
improving the charging speed, reducing the battery heat so as to
ensure the safety and reliability when the terminal is charged.
Additionally, because the power adapter outputs the voltage with
the pulsating waveform, there is no necessity to dispose
electrolytic capacitors in the power adapter. Not only can the
power adapter be simplified and miniaturized, but the cost can also
be greatly reduced. Additionally, two current sampling modes are
alternatively switched to sample the current, which ensures the
sensing function with the compatibility between sensing precision
and dynamic range and expands the scope of the applications.
[0268] In the disclosure, it is should be understood that spatially
relative terms, such as "center", "longitudinal", "lateral",
"length", "width", "above", "below", "front", "back", "left",
"right", "horizontal", "vertical", "top", "bottom", "inner",
"outer", "clockwise", "counterclockwise", "axial", "radial",
"circumferential", and the like, may be used herein for ease of
description to describe one element or feature's relationship to
another element(s) or feature(s) as illustrated in the figures. It
will be understood that the spatially relative terms are intended
to encompass different orientations of the device in use or
operation in addition to the orientation depicted in the figures.
The spatially relative terms are not limited to specific
orientations depicted in the figures.
[0269] In addition, the term "first", "second" are for illustrative
purposes only and are not to be construed as indicating or imposing
a relative importance or implicitly indicating the number of
technical features indicated. Thus, a feature that limited by
"first", "second" may expressly or implicitly include at least one
of the features. In the description of the present disclosure, the
meaning of "plural" is two or more, unless otherwise specifically
defined.
[0270] All of the terminologies containing one or more technical or
scientific terminologies have the same meanings that persons
skilled in the art understand ordinarily unless they are not
defined otherwise. For example, "arrange," "couple," and "connect,"
should be understood generally in the embodiments of the present
disclosure. For example, "firmly connect," "detachably connect,"
and "integrally connect" are all possible. It is also possible that
"mechanically connect," "electrically connect," and "mutually
communicate" are used. It is also possible that "directly couple,"
"indirectly couple via a medium," and "two components mutually
interact" are used.
[0271] All of the terminologies containing one or more technical or
scientific terminologies have the same meanings that persons
skilled in the art understand ordinarily unless they are not
defined otherwise. For example, "upper" or "lower" of a first
characteristic and a second characteristic may include a direct
touch between the first and second characteristics. The first and
second characteristics are not directly touched; instead, the first
and second characteristics are touched via other characteristics
between the first and second characteristics. Besides, the first
characteristic arranged on/above/over the second characteristic
implies that the first characteristic arranged right
above/obliquely above or merely means that the level of the first
characteristic is higher than the level of the second
characteristic. The first characteristic arranged
under/below/beneath the second characteristic implies that the
first characteristic arranged right under/obliquely under or merely
means that the level of the first characteristic is lower than the
level of the second characteristic.
[0272] In the description of this specification, the description of
the terms "one embodiment", "some embodiments", "examples",
"specific examples", or "some examples", and the like, means to
refer to the specific feature, structure, material or
characteristic described in connection with the embodiments or
examples being included in at least one embodiment or example of
the present disclosure. In the present specification, the term of
the above schematic representation is not necessary for the same
embodiment or example. Furthermore, the specific feature,
structure, material, or characteristic described may be in
combination in a suitable manner in any one or more of the
embodiments or examples. In addition, it will be apparent to those
skilled in the art that different embodiments or examples described
in this specification, as well as features of different embodiments
or examples, may be combined without contradictory
circumstances.
[0273] One having ordinary skill in the art may be aware that the
units and steps of algorithm in the examples of the embodiments
published by this application can be realized by electronic
hardware, or combinations of computer software and electronic
hardware. Whether the functions should be performed by hardware or
software should depend upon the particular applications and design
constraints of a technical solution. One skilled in the art may use
different methods to implement the described functions for each
specific application, but such implementation should not be
considered as outside of the scope of the present disclosure.
[0274] One skilled in the art may clearly understand that they can
refer to the corresponding process in the abovementioned
embodiments of the method for the specific operating process of the
abovementioned system, device, and circuits. No description is
provided herein again for the convenience and succinctness of the
description.
[0275] In the several embodiments provided by the application, it
should be understood that the revealed system, device and method
may be implemented in other ways. For example, the abovementioned
embodiments of the device are merely schematic. For example, the
division of the circuits is merely a division based on logical
functions; it may be different when they are put into practice. For
example, a plurality of circuits or components may be combined or
integrated into another system, or some features may be ignored or
not be performed. And another point is that the displayed or
discussed coupling, direct coupling or communication can be done
through some interfaces, devices, or indirect coupling or
communication between circuits; they may be electrical, mechanical,
or in other forms.
[0276] The circuits described as separated parts may or may not be
physically separated. A part that appeared as a circuit may or may
not be a physical circuit, i.e. it can locate in one place, or it
can be distributed to multiple network circuits. Part of or all of
the circuits can be selected based on actual needs to achieve the
object of the solutions of the present embodiments.
[0277] Furthermore, each of the functional circuits in the
embodiments of the present disclosure may be integrated in one
processing circuit, or may be independent circuits physically
separated, or may integrate with another one or more circuits and
appear as a single circuit.
[0278] If the function is realized as a software functional unit
and used or sold as a standalone product, it may be stored in a
computer-readable storage medium. Based on such understanding, the
technical solutions of the present disclosure per se, or its
contribution to the related art, or the technical solution may be
realized in a software product. The computer software product is
stored in a storage medium, including several commands that enable
a computer device (may be a personal computer, a server, or network
device) to perform all or part of the steps of the methods of the
various embodiments of the present disclosure. The storage medium
includes U-disk, removable hard disk, read-only memory (ROM),
random access memory (RAM), magnetic disk or compact disc (CD) and
other medium that can store program codes.
[0279] The above texts are merely specific embodiments of the
present disclosure. However, the scope of the present disclosure is
not limited hereto. Any variations or alternatives that can easily
be thought of by technicians familiar with the field should fall
within the scope of the present disclosure. Therefore, the scope of
the present disclosure should be defined by the scope of the
claims.
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